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Relatywnie inny doping.Genetyczna sukcesywność.

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Doping

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Witam!

Na pierwszym planie pozwolę sobie wrzucić trochę info odnośnie dopingu genetycznego z różnych źródeł co miałoby na celu lekko objaśnić jak to wygląda laikom tematu.


NIECZYSTE ZAGRANIE

(źródło: Rzeczpospolita)

ZOZ BAŁUTY OSTRZEGA I ZAKAZUJE STOSOWANIA!

Rywalizacja o sportowe medale już dawno przeniosła się z boisk i bieżni do laboratoriów naukowych. Środki dopingujące pozwalają na podniesienie wydolności organizmu i przyrost masy mięśniowej, jednak za cenę chorób układu krążenia, zaburzeń hormonalnych i innych dolegliwości.

Doping dzieli się na farmakologiczny i genetyczny.

Doping farmakologiczny:

* sterydy anaboliczne - syntetyczne wersje męskiego hormonu - testosteronu. Zalicza się do nich: THG (tetrahydrogestrinon), clenbuterol, nandrolon, stanazolol. Umożliwiają wzrost masy mięśniowej i siły. Powodują wzrost agresji i zmniejszają zmęczenie podczas treningu. Zastosowanie: sporty siłowe takie jak sprinty czy podnoszenie ciężarów.
* hormony peptydowe - erytropoetyna (EPO), hormon wzrostu (HGH), insulina. EPO umożliwia szybszy transport tlenu we krwi - w konsekwencji większy i dłuższy wysiłek sportowy. HGH wspomaga spalanie tłuszczu i wzrost mięśni. Zastosowanie: sporty wytrzymałościowe, takie jak wioślorstwo, kolarstwo, biegi długodystansowe.
* kortykosteroidy np. hydrokortyzon. Redukują stany zapalne przy kontuzjach ściengien. Zastosowanie: niektóre sporty siłowe, baseball, rzut oszczepem, gimnastyka, zapasy.
* narkotyki, opiumaty: diamorfina (heroina), metadon, morfina, petydyna, marihuana. Zwiększa odporność na ból, relaksują. Zastosowanie: pływanie, biegi długodystansowe.
* beta-blokery: acebutolol, alprenonol, nadolol, propranolol. Zmniejszają częstotliwość pracy serca i ciśnienie krwi, redukują drżenie mięśni. Zabronione w łucznictwie, gimnastyce, pięcioboju nowoczesnym, strzelnictwie, pływaniu, zapasach.

Doping genetyczny - wprowadzenie do komórek mięśni odpowiedniej informacji genetycznej np. za pomocą nieszkodliwego wirusa. Cały proces odbywać się może w laboratorium.

Skutki uboczne dopingu:

* łysienie,
* owłosienie twarzy (kobiety),
* powiększenie piersi (mężczyźni),
* uszkodzenia nerek i wątroby,
* skurcze jąder, impotencja,
* nadmierny wzrost narządów,
* szorstkość skóry,
* odnowienia kontuzji,
* problemy oddechowe,
* uzależnienie,
* mdłości,
* cukrzyca,
* jaskra,
* utrata mięśni,
* nadciśnienie.



Tutaj fragment z gazeta.pl

..Pekin: igrzyska mutantów?

A już niedługo pojawi się nowy wróg czystej sportowej rywalizacji, przy którym testosteron czy popularne w ostatnich latach EPO będą jawić się jako preparat witaminowy. Wielkimi krokami zbliża się bowiem era dopingu genetycznego, który z przeciętnego zawodnika będzie w stanie zrobić superistotę. Jak? Dzięki ingerencji w kod genetyczny (np. wszczepianie obcych tkanek czy podawanie specjalnych wirusów) możliwa będzie nadludzka siła i wytrzymałość, a zmodyfikowane ścięgna zniosą każdy wysiłek.

- To jest prawdziwy problem. Sportowiec wspomagający się farmakologicznie prędzej czy później wpadnie w trakcie kontroli. W przypadku dopingu genetycznego nie ma takiej gwarancji - uważa trener polskich 400-metrowców Józef Lisowski.

Według specjalistów w wykryciu takiego rodzaju dopingu bezużyteczne okazać mogą się nawet testy DNA czy biopsja mięśni, a pierwsze efekty ulepszania genów zobaczymy już za dwa lata na igrzyskach w Pekinie. Właśnie gospodarze najbliższej olimpiady oraz Amerykanie uchodzą za liderów w pracach nad dopingiem genetycznym. Nie ma się czemu dziwić. Chińczycy mogą liczyć na gigantyczne sumy od władz, które będą chciały pokazać światu, kto jest najszybszy i najsilniejszy. W Stanach Zjednoczonych pełną parą pracują laboratoria podobne do tych, jakimi dysponowała firma BALCO. To właśnie ona wyprodukowała THG, środek przez wiele lat niemożliwy do wykrycia. Zażywały go takie tuzy sportu jak Marion Jones, Tim Montgomery czy wspomniany Bonds. W obu przypadkach wszystko odbywa się w oparciu o technologię rodem z filmów science-fiction.

- Nawet WADA niewiele może tutaj zdziałać. Najgorsze, że niewiele wiemy na ten temat. Opieramy się tylko na domysłach i przypuszczeniach - opowiada Dariusz Błachnio z polskiej komisji antydopingowej. - Na razie nie słyszałem, by wspomaganie genetyczne wykorzystano w "normalnej" medycynie. Jedno jest pewne, jeśli doping genetyczny się pojawi, będzie to istna apokalipsa w sporcie..




to wziete z poradnikmedyczny.pl


..Coraz częściej w terapii wykorzystuje się mechanizmy genetyczne, uderzając bezpośrednio w przyczynę choroby. Jest to prawdopodobnie najsilniej wspierana badaniami dziedzina medycyny. Kariera genetycznych eksperymentów zaczyna także rozwijać się w sportowym świecie. Klasyczne metody dopingu wychodzą już z mody. Przyszłością jest genetyczny doping, którego największą zaletą, a dla innych oczywistą wadą jest trudość w jego ujawnieniu i kontroli.

Francuscy naukowcy próbują rozwiązać problem wykrywania genetycznego dopingu. Na chwilę obecną nie istnieją takie metody, ale ukazanie wielkości problemu może w niedalekiej przyszłości zaowocować skutecznymi testami. Wykrycie syntetycznej erytropoetyny w organizmie człowieka nie stanowi wielkiego wyzwania dla testów antydopingowych, ale w jaki sposób ujawnić stosowanie "zastrzyków" z genami dla tego enzymu? Choć na razie tego rodzaju doping nie jest powszechnie stosowany to z pewnością w niedalekiej przyszłości problem stanie się codziennością w rywalizacji sportowej.

Dotychczasowe badania na zwierzętach pokazują, że stosowanie genów EPO powoduje niezahamowaną proliferację komórek lini czerwonokrwinkowej prowadząc do licznych zakrzepów, ogólnoustojowej odpowiedzi alergicznej, a w efekcie szybkiego zgonu. Takie powikłanie to kolejny problem, nad którego rozwiązaniem pracować będą zastępy naukowców, a rynek dopingowych specyfików z niecierpliwością czeka na błyskotliwe rozwiązania..



Świetny post Aliena,który odzwierciedla duzo informacji na ten temat.
http://www.sfd.pl/igf-1,DES_1-3_igf-1-t318485.html


.. tutaj z jednego z zagranicznych bordów wzięte:

..A new form of gene therapy being developed to help people with muscle-wasting disease could be used to enhance athletic performance through "gene doping".


The scientist leading the research, Lee Sweeney of the University of Pennsylvania, told the American Association for the Advancement of Science about a new study in his laboratory in which genes for a growth factor called IGF-1 were injected into the hind legs of rats. The animals then spent a few weeks on a "weight training protocol".


The muscles in the legs injected with IGF-1 gained twice as much strength as the uninjected legs, Dr Sweeney said. "Additionally, the rate at which the strength was lost in the injected muscles once the training was stopped was very slow compared to the uninjected," he said. "Even without any training, injection of [IGF-1 genes] gave a 15 per cent strength increase."


The purpose of developing IGF-1 gene therapy is to treat muscular disorders, including muscle loss associated with disuse or ageing. But Dr Sweeney said the tests showed it "could also be used in healthy adults to build muscle strength and make muscle more resistant to damage".


"This is but one example of a number of gene therapies being developed with disease treatment as the goal but, if given to a healthy individual, would provide genetic enhancement of some trait," he said.


"The prospects are particularly high that muscle-directed gene therapy will be used by the athletic community for performance enhancement."


Such gene doping would be hard to detect. Richard Pound, chancellor of McGill University in Montreal, Quebec, who is chairman of the World Anti-Doping Agency told the meeting the development of genetic enhancements for athletes paralleled that of performance-enhancing drugs 30 or 40 years ago, when detection techniques and regulatory mechanisms were not in place. He said: "With genetic enhancement we want to make sure we're in there from the start."

Zakładam,ze większość zna angielski,bo nie mam obecnie weny na slęczenie sie z tym i tłumaczenie.



to wzięte z taipeitimes.com

.. In recent years, the International Olympic Committee and other sports organizations have worried about the possible misuse of gene-transfer technology. But the sports world seems intent on exploiting this technology in pursuit of gold medals and championships, and genetic testing may be the wave of the future.

Two Australian Football League teams have hinted that they are looking into tests that would indicate an athlete's likely height, stamina, speed and strength. Indeed, for some, "gene doping" now represents the Holy Grail of performance enhancement, while for others it means the end of sports as we know it.

The prospect of a future of genetically modified athletes incites alarm throughout the sports world, accompanied by portrayals of such athletes as inhuman or some form of mutant.

This is a misrepresentation of how gene transfer would alter humans, both therapeutically and non-therapeutically, should it ever be legalized. But the fear that rogue scientists will take advantage of athletes -- or that athletes will seek to enroll in gene-transfer experiments in an attempt to receive some undetectable performance benefit -- is very real.

The World Anti-Doping Agency (WADA) prohibited gene doping in 2003, but some scientists predict that its misuse in sport is likely to appear at the Beijing 2008 Olympics. It is in this context that the debate about gene doping erupted during last year's Olympics in Athens. Unfortunately, because the discussion has so far been dominated by moral panic over the state of sports, many ethical considerations and important questions have been excluded.

Get local

Policies concerning gene doping should not rely solely on the interests and infrastructures of sports organizations. In particular, the monitoring committees on genetic technology that nations develop must be taken on board by the world of sport. A simple model based on prohibition and testing for gene modification will not be enough, assuming that detection is possible at all.

Moreover, ethics committees must be made aware of the special circumstances of sports, which limit the effectiveness of broader social policies on genetic modification. Again, regulation ought not to rely on one single global authority.

As has been made clear from the ethical debates on stem-cell research, a global policy cannot easily be adopted or enforced, nor should it be.

Above all, it is not acceptable for the world of sport to impose a moral view about the role of enhancement technology on nations that wish to parti****te in the Olympics, without implementing an extensive and ongoing consultative process to accompany its policy decision. This cannot involve the creation of working groups that merely pay lip service to ethical debate, but must enable non-sports organizations to develop their own policy framework for the regulation of "gene doping" and, more broadly, the use of genetic information.

Policies governing gene transfer in sports must, therefore, be recognized as subservient to broader bio-ethical and bio-legal interests that recognize the changing role of genetics in society. The rhetoric surrounding "gene doping" relies heavily on its moral status as a form of cheating. Yet, this status relies on existing anti-doping rules. If we don't ban gene transfer in the first place, then on one level, it is not cheating.

Mutants

In any case, to describe genetically modified athletes as mutants or inhuman is morally suspect, for it invokes the same kind of prejudice that we deplore in relation to other biological characteristics, particularly race, gender and disability. After all, many, if not most, top athletes are "naturally" genetically gifted. To refer to these people as mutants would surely invite widespread criticism.

Those who fear that gene doping heralds the "end of sports" should instead recognize this moment as an opportunity to ask critical and difficult questions about the effectiveness and validity of anti-doping tests. Does society really care about performance enhancement in sport?

That may sound like a radical question. But advancement in ethical inquiry relies on the conflict of beliefs and values. For many years, commentators have expressed concerns about the culture of doping in elite sport. Yet, the culture of anti-doping is equally alarming, because it embodies a dogmatic commitment that limits the capacity for critical debate over what really matters in sport.

If anti-doping authorities truly care about sports, then they have a responsibility to re-examine the basic values that underpin their work. They should begin by imagining what would happen if the child of a genetically modified human wanted to become an elite athlete. At the very least, they might then be less prone to imposing the narrow moral position of the sports world on the parent...


tutaj art.pewnego mądrego fizolofa,któy miałem gdzies w notatkach;

..How effective really is injectable IGF?
Finally research had been done that shows us exactly how effective the IGF we use to inj is compared to the gene doping research that most of the studies boasting IGF claims are based on. This first study compared directly the IGF-gene tranfer to adminstering the IGF-I peptide systemically. Gene transfer was superior by no surprise, but what is good news is that IGF-I hastened functional recovery, regardless of the route of IGF-I administration. The systemic IGF took a whole 7 days to give the same muscle recovery as the gene doping did, (21 dasy compared to 14). This is because it is easier for gene doping to result in the intracellular signaling.
Below is another study that shows that systemic IGF is effective at repairing muscles in mice with MD.
Comparative evaluation of IGF-I gene transfer and IGF-I protein administration for enhancing skeletal muscle regeneration after injury.

· Schertzer JD,

· Lynch GS.

1Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Victoria, Australia.

Developing methodologies to enhance skeletal muscle regeneration and hasten the restoration of muscle function has important implications for minimizing disability after injury and for treating muscle diseases such as Duchenne muscular dystrophy. Although delivery of various growth factors, such as insulin-like growth factor-I (IGF-I), have proved successful in promoting skeletal muscle regeneration after injury, no study has compared the efficacy of different delivery methods directly. We compared the efficacy of systemic delivery of recombinant IGF-I protein via mini-osmotic pump ( approximately 1.5 mg/kg/day) with a single electrotransfer-assisted plasmid-based gene transfer, to hasten functional repair of mouse tibialis anterior muscles after myotoxic injury. The relative efficacy of each method was assessed at 7, 21 and 28 days post-injury. Our findings indicate that IGF-I hastened functional recovery, regardless of the route of IGF-I administration. However, gene transfer of IGF-I was superior to systemic protein administration because in the regenerating muscle, this delivery method increased IGF-I levels, activated intracellular signals (Akt phosphorylation), induced a greater magnitude of myofiber hypertrophy and hastened functional recovery at an earlier time point (14 days) after injury than did protein administration (21 days). Thus, the relative efficacy of different modes of delivery is an important consideration when assessing the therapeutic potential of various proteins for treating muscle injuries and skeletal muscle diseases.Gene Therapy advance online publication, 27 July 2006; doi:10.1038/sj.gt.3302817.

Systemic administration of IGF-I enhances oxidative status and reduces contraction-induced injury in skeletal muscles of mdx dystrophic mice.

* Schertzer JD,
* Ryall JG,
* Lynch GS.

Dept. of Physiology, The Univ. of Melbourne, Victoria 3010, Australia. gsl@unimelb.edu.au).

The absence of dystrophin and resultant disruption of the dystrophin glycoprotein complex renders skeletal muscles of dystrophic patients and dystrophic mdx mice susceptible to contraction-induced injury. Strategies to reduce contraction-induced injury are of critical importance, because this mode of damage contributes to the etiology of myofiber breakdown in the dystrophic pathology. Transgenic overexpression of insulin-like growth factor-I (IGF-I) causes myofiber hypertrophy, increases force production, and can improve the dystrophic pathology in mdx mice. In contrast, the predominant effect of continuous exogenous administration of IGF-I to mdx mice at a low dose (1.0-1.5 mg.kg(-1).day(-1)) is a shift in muscle phenotype from fast glycolytic toward a more oxidative, fatigue-resistant, slow muscle without alterations in myofiber cross-sectional area, muscle mass, or maximum force-producing capacity. We found that exogenous administration of IGF-I to mdx mice increased myofiber succinate dehydrogenase activity, shifted the overall myosin heavy chain isoform composition toward a slower phenotype, and, most importantly, reduced contraction-induced damage in tibialis anterior muscles. The deficit in force-producing capacity after two damaging lengthening contractions was reduced significantly in tibialis anterior muscles of IGF-I-treated (53 +/- 4%) compared with untreated mdx mice (70 +/- 5%, P < 0.05). The results provide further evidence that IGF-I administration can enhance the functional properties of dystrophic skeletal muscle and, compared with results in transgenic mice or virus-mediated overexpression, highlight the disparities in different models of endocrine factor delivery.
__________________
Researcher, Biochemist, Personal Trainer, Footballer



Zapraszam do tematu szczególnie większe głowy tj.Bronka i calą ekipe zarządzającą z jelitem na czele,Vadima,Jarusia co siedzi za wielką wodą i wszystkich co sie tym po kryjomu interesują.
Zdr.


Prosiłbym o poruszanie pewnego typu informacji edukacyjnych jak również praktycznych.Wszystkie informacje sie przydadzą.
Obecnie jestem w trakcie wyszukiwania informacji odnośnie zabawy z aminopeptydami jak również wpływ ich nazdwyżek na budowe ciala..

CDN.

sprzedam biznes w calosci.

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In 1997, scientists McPherron and Lee revealed to the public the &#8216;secret&#8217; of an anomaly that livestock breeders have capitalized since the late 1800&#8217;s: the gene responsible for big beefy cows (1). More than a century ago, livestock breeders in Europe observed that some of their cattle were more muscled than others. Being dabblers in genetics, they selectively bred these cattle to increase the progeny displaying this trait. Thus two breeds of cattle (Belgian Blue and Piedmontese) were developed that typically exhibit an increase in muscle mass relative to other conventional cattle breeds. Little did they know that many years later Mighty Mouse would be more than merely a cartoon.

A team of scientists led by McPherron and Lee at John Hopkins University was investigating a group of proteins that regulate cell growth and differentiation. During their investigations they discovered the gene that may be responsible for the phenomenon of increased muscle mass, also called &#8216;double-muscling&#8217; (1, 2). Myostatin, the protein that the gene encodes, is a member of a superfamily of related molecules called transforming growth factors beta (TGF-b ). It is also referred to as growth and differentiation factor-8 (GDF-8). By knocking out the gene for myostatin in mice, they were able to show that the transgenic mice developed two to three times more muscle than mice that contained the same gene intact. Lee commented that the myostatin gene knockout mice "look like Schwarzenegger mice." (3).



Further exploration of genes present in skeletal muscle in the two breeds of double-muscled cattle revealed mutations in the gene that codes for myostatin. The double-muscling trait of the myostatin gene knockout mice and the double-muscled cattle demonstrates that myostatin performs the same biological function in these two species. Apparently, myostatin may inhibit the growth of skeletal muscle. Knocking out the gene in transgenic mice or mutations in the gene such as in the double-muscled cattle result in larger muscle mass. This discovery has paved the way for a plethora of futuristic implications from breeding super-muscled livestock to treatment of human muscle wasting diseases.

Researchers are developing methods to interfere with expression and function of myostatin and its gene to produce commercial livestock that have more muscle mass and less fat content. Myostatin inhibitors may be developed to treat muscle wasting in human disorders such as muscular dystrophy. However, several public media sources immediately raised the issue of abusing myostatin inhibitors by athletes. In addition, a hypothesis has been put forth that a genetic propensity for high levels of myostatin is responsible for the lack of muscle gain in weight trainees. Accordingly, this article presents a look at the science of myostatin and its implications for the athletic arena.


--------------------------------------------------------------------------------

WHAT IS MYOSTATIN?

Growth Factors

Before we can understand the implications of tampering with myostatin and its gene, we must learn what myostatin is and what it does. Higher organisms are comprised of many different types of cells whose growth, development and function must be coordinated for the function of individual tissues and the entire organism. This is attainable by specific intercellular signals, which control tissue growth, development and function. These molecular signals elicit a cascade of events in the target cells, referred to as cell signaling, leading to an ultimate response in or by the cell.

Classical hormones are long-range signaling molecules (called endocrine). These substances are produced and secreted by cells or tissues and circulated through the blood supply and other bodily fluids to influence the activity of cells or tissues elsewhere in the body. However, growth factors are typically synthesized by cells and affect cellular function of the same cell (autocrine) or another cell nearby (paracrine). These molecules are the determinants of cell differentiation, growth, motility, gene expression, and how a group of cells function as a tissue or organ.

Growth factors (GF) are normally effective in very low concentrations and have high affinity for their corresponding receptors on target cells. For each type of GF there is a specific receptor in the cell membrane or nucleus. When bound to their ligand, the receptor-ligand complex initiates an intracellular signal inside of the cell (or nucleus) and modifies the cell&#8217;s function.

A GF may have different biological effects depending on the type of cell with which it interacts. The response of a target cell depends greatly on the receptors that cell expresses. Some GFs, such as insulin-like growth factor-I, have broad specificity and affect many classes of cells. Others act only on one cell type and elicit a specific response.

Many growth factors promote or inhibit cellular function and may be multifactoral. In other words, two or more substances may be required to induce a specific cellular response. Proliferation, growth and development of most cells require a specific combination of GFs rather than a single GF. Growth promoting substances may be counterbalanced by growth inhibiting substances (and vice versa) much like a feedback system. The point where many of these substances coincide to produce a specific response depends on other regulatory factors, such as environmental or otherwise.

Transforming Growth Factors

Some GFs stimulate cell proliferation and others inhibit it, while others may stimulate at one concentration and inhibit at another. Based on their biological function, GFs are a large set of proteins. They are usually grouped together on the basis of amino acid sequence and tertiary structure. A large group of GFs is the transforming growth factor beta (TGFb ) superfamily of which there are several subtypes. They exert multiple effects on cell function and are extensively expressed.

A common feature of TGFb s is that they are secreted by cells in an inactive complex form. Consequently, they have little or no biological activity until the latent complex is broken down. The exact mechanism(s) involved in activating these latent complexes is not completely understood, but it may involve specific enzymes. This further exemplifies how growth factors are involved in a complex system of interaction.

Another common feature of TGFb s is that their biological activity is often exhibited in the presence of other growth factors. Hence, we can see that the bioactivity of TGFb s is complex, as they are dependent upon the physiological state of the target cell and the presence of other growth factors.

Myostatin

There are several TGFb s subtypes which are based on their related structure. One such member is called growth and differentiation factors (GDF) and specifically regulates growth and differentiation. GDF-8, also called myostatin, is the skeletal muscle protein associated with the double muscling in mice and cattle.

McPherron et al detected myostatin expression in later stages of development of mouse embryos and in a number of developing skeletal muscles (1). Myostatin was also detected in adult animals. Although myostatin mRNA was almost exclusively detected in skeletal muscle, lower concentrations were also found in adipose tissue.

To determine the biological role of myostatin in skeletal muscle, McPherron and associates disrupted the gene that encodes myostatin protein in rats, leading to a loss its function. The resulting transgenic animals had a gene that was rendered non-functional for producing myostatin. The breeding of these transgenic mice resulted in offspring that were either homozygous for both mutated genes (i.e. carried both mutated genes), homozygous for both wild-type genes (i.e. carried both genes with normal function) or heterozygous and carrying one mutated and one normal gene. The main difference in resulting phenotypes manifested in muscle mass. Otherwise, they were apparently healthy. They all grew to adulthood and were fertile.

Homozygous mutant mice (often called gene knockout mice) were 30% larger than their heterozygous and wild-type (normal) littermates irregardless of sex and age. Adult mutant mice had abnormal body shapes with very large hips and shoulders and the fat content was similar to the wild-type counterparts. Individual muscles from mutant mice weighed 2-3 times more than those from wild-type mice. Histological analysis revealed that increased muscle mass in the mutant mice was resultant of both hyperplasia (increased number of muscle fibers) and hypertrophy (increased size of individual muscle fibers).

Since this discovery, McPherron and other researchers investigated the presence of myostatin and possible gene mutations in other animal species. Scientists have reported the sequences for myostatin in 9 other vertebrate animals, including pigs, chickens and humans (2, 4). Research teams separately discovered two independent mutations of the myostatin gene in two breeds of double-muscled cattle: the Belgian Blue and Piedmontese (2, 5). A deletion in the myostatin gene of the Belgian Blue eliminates the entire active region of the molecule and is non-functional; and this mutation causes hypertrophy and increased muscle mass. The Piedmontese coding sequence for myostatin contains a missense mutation. That is, a point in the sequence encodes for a different amino acid. This mutation likely leads to a complete or nearly completes loss of myostatin function.

McPherron et al analyzed DNA from other purebred cattle (16 breeds) normally not considered as double-muscled and found only one similar mutation in the myostatin gene (2). The mutation was detected in one allele a single animal which was non-double-muscled. Other mutations were detected but these did not affect protein function.

Earlier studies reported high levels of myostatin in developing cattle and rodent skeletal muscles (2, 7). Furthermore, mRNA expression varied in individual muscles. Consequently, it was thought that myostatin was relegated to skeletal muscle and that the gene&#8217;s role was restricted to the development of skeletal muscle. However, A New Zealand team of researchers recently reported the detection of myostatin mRNA and protein in cardiac muscle (8).

TGF-b superfamily members are found in a wide variety of cell types, including developing and adult heart muscle cells. Three known isoforms of TGF-b (TGF-b 1, -b 2, and -b 3) are expressed differentially at both the mRNA and protein levels during development of the heart (9). This suggests that these isoforms have different roles in regulating tissue development and growth. Therefore, Sharma and colleagues investigated distribution of the myostatin gene in other organ tissues using more sensitive detection techniques than that used by earlier researchers (8).

They found a DNA sequence in sheep and cow heart tissue that was identical to the respective skeletal muscle myostatin protein sequence, indicating the presence of myostatin gene in these tissues. In heart tissue from a Belgian Blue fetus, the myostatin gene deletion present in skeletal tissue was detected. They detected the unprocessed precursor and processed myostatin protein in normal sheep and cattle skeletal muscle, but not in that of the Belgian Blue. As well, only the unprocessed myostatin protein was found in adult heart tissue.

Animals with induced myocardial infarction (causing death of cells in heart tissue) displayed high levels of myostatin protein, even at 30 days postinfarct, in cells immediately surrounding the dead lesion. However, undamaged cells bordering the infarcted area contained very low levels of myostatin protein similar to control tissue. Considering the increase in other TGF-b levels in experimentally infarcted heart tissue (10), these growth factors may be involved in promotion of tissue healing.

Shaoquan and colleagues at Purdue University detected myostatin mRNA in the lactating mammary glands of pigs, possibly serving a regulatory role in the neonatal pig (12). They also detected similar mRNA is porcine skeletal tissue, but not in connective tissue. Most studies, in addition to this one, confirm that high levels of myostatin mRNA in prenatal animals and reduced levels postnatal at birth and postnatal reflect a regulatory role of myostatin in myoblast (muscle cell precursors) growth, differentiation and fusion.

A mutation in the myostatin gene in the two cattle breeds is not as advantageous as in mice. The cattle have only modest increases in muscle mass compared to the myostatin knockout mice (20-25% in the Belgian Blue and 200-300% in the null mice). Also, the cattle with myostatin mutations have reduced size of internal organs, reductions in female fertility, delay in sexual maturation, and lower viability of offspring (6). Although no heart abnormalities in myostatin-null mice were reported, the hearts in adult Belgian Blue cattle are smaller (11). Although the reduction in organ weight has been attributed to skeletal muscle mass increases, this has yet to be confirmed. Since there is evidence that the effects of myostatin mutation on heart tissue are variable in different species, there may be other possible tissue variabilities as well. Additionally, research detected myostatin mRNA in tissues other than skeletal muscle, demonstrating its expression is not relegated to skeletal muscle tissue as originally thought. Only further research will elucidate these possibilities.

Although several TGF-b superfamily members are found in skeletal and cardiac muscle tissue, their exact roles in development is not yet clear. Apparently, based on the early studies, the myostatin protein may have diverse roles in developmental and adult stage tissues. Sharma et al proposes that "myostatin has different functions at different stages of heart development" (8). As we shall see, the same can conceivably apply to skeletal muscle as well.

Myostatin and regulation of skeletal muscle

While many of the studies demonstrate that myostatin is involved with prenatal muscle growth, we know little of its association with muscle regeneration. Muscle regeneration of injured skeletal muscle tissue is a complex system and ability for regeneration changes during an animal&#8217;s lifetime. Exposure of tissues to various growth factors is altered during a lifetime. In embryos and young animals, hormones and growth factors favor muscle growth. However, many of these factors are downregulated in adults. Alteration in growth factors inside and outside of the muscle cells may diminish their capacity to maintain protein expression. Although protein mRNA may be detected within the cell, there are many sites of protein regulation beyond mRNA levels. As mentioned above, myostatin protein occurs in an unprocessed (inactive) and processed (active) form. Therefore, bioactivity of myostatin may be regulated at any point of its synthesis and secretion.

Keep in mind that nearly all regulatory systems in the body are under positive and negative control. This includes cardiac and skeletal muscle tissues. Myoblasts in developing animal embryos respond to different signals that control proliferation and cell migration. In contrast, differentiated muscle cells respond to another set of different signals. Distinct ratios of signals regulate the transition from undetermined cells to differentiated cells and ensure normal formation and differentiation in cellular tissues. However, many of the factors that regulate the various development pathways in muscle tissue are still poorly understood.

MyoD, IGF-I and myogenin (growth promoters in muscle cells) gene products are associated with muscle cell differentiation and activation of muscle-specific gene expression (14). Muscle-regulatory factor-4 (MRF-4) mRNA expression increases after birth and is the dominant factor in adult muscle. This growth factor is thought to play an important role in the maintenance of muscle cells. In addition to myostatin, there are other inhibitory gene products, such as Id (inhibitor of DNA binding). Although in vitro experiments are revealing the mechanisms of these specific proteins, we know less regarding their roles in vivo.

Although we know that lack of myostatin protein is associated with skeletal muscle hypertrophy in McPherron&#8217;s gene knockout mice and in double-muscled cattle, we know little about the physiological expression of myostatin in normal skeletal muscle. Recent studies in animal and human models indicate a paradox in myostatin&#8217;s role on growth of muscle tissue.

For example, evidence shows that myostatin may be fiber-type specific. Runt piglets, which have lower birth weights than their normal littermates, had lower proportions of Type I skeletal muscle fibers in specific muscles (12). Similar observations were made in rats where undetectable levels of myostatin mRNA in atrophied mice soleus (Type I fibers) (13). Transient upregulation of myostatin mRNA was detected in atrophied fast twitch muscles but not in slow twitch muscles. Thus, myostatin may modulate gene expression controlling muscle fiber type.

Studies also demonstrated lack of metabolic effects on myostatin expression in piglets and mice (12, 13). Food restriction in both piglets and mice did not affect myostatin mRNA levels in skeletal muscle. Neither dietary polyunsaturated fatty acids nor exogenous growth hormone administration in growing piglets altered myostatin expression (12). These and other studies strongly suggest that the physiological role of myostatin is mostly associated with prenatal muscle growth where myoblasts are proliferating, differentiating and fusing to form muscle fibers.

Although authors postulate that myostatin exerts its effect in an autocrine/paracrine fashion, serum myostatin has been detected demonstrating that it is also secreted into the circulation (8, 4). It is believed that the protein detected in human serum is of processed (active form) myostatin rather than the unprocessed form. High levels of this protein have been associated with muscle wasting in HIV-infected men compared to healthy normal men (4). However, this association does not necessarily verify that myostatin directly contributes to muscle wasting. We do not know if myostatin acts directly on muscle or on other regulatory systems that regulate muscle growth. Although several authors postulate that myostatin may present a larger role in muscle regeneration after injury, this has yet to be confirmed.

Myostatin and athletes

Further complicating the issue of myostatin&#8217;s role in regulation of muscle growth is the report by a team of scientists that mutations in the human myostatin gene had little impact on responses in muscle mass to strength training (15, unpublished data). Based on the report that muscle size is a heritable trait in humans (16), Ferrell and colleagues investigated the variations in the human myostatin gene sequence. They also examined the influence of myostatin variations in response of muscle mass to strength training.

Study subjects represented various ethnic groups and were classified by the degree of muscle mass increases they experienced after strength training. Included were competitive bodybuilders ranking in the top 10 world-wide and in lower ranks. Also included were football players, powerlifters and previously untrained subjects. Quadricep muscle volume of all subjects was measured by magnetic resonance imaging before and after nine weeks of heavy weight training of the knee extensors. Subjects were grouped and compared by degree of response and by ethnicity.

There were several genetic coding sequence variations detected in DNA samples from subjects. Two changes were detected in a single subject and another two were observed in two other individuals. They were heterozygous with the wild-type allele, meaning they had one allele with the mutation and the other allele was normal. The other variations were present in the general population of subjects and determined common. One of the variations was common in the group of mixed Caucasian and African-American subjects. However, the less frequent allele had a higher frequency in African-Americans. Although, as the authors comment, "these variable sites [in the gene sequence] have the potential to alter the function of the myostatin gene product and alter nutrient partitioning in individuals heterozygous for the variant allele", the data from this and other studies so far show that this may not occur. This study did not demonstrate any significant response between genotypes and response to weight training. Nor were there any significant differences between African-American responders to strength training and non-responders or between Caucasian responders and non-responders.

Further research will be necessary to determine whether myostatin has an active role in muscle growth after birth and in adult tissues. To ascertain benefit to human health, we also need to discover its role in muscle atrophy and regeneration after injury. Only extended research will reveal any such benefits.

The future of myostatin

Now that we have reviewed some of the biology of the myostatin protein, its gene, and the relevant scientific literature, what are the implications for its application?

Many authors of the myostatin studies have speculated that interfering with the activity of myostatin in humans may reverse muscle wasting disease associated with muscular dystrophy, AIDS and cancer. Some predict that manipulation of this gene could produce heavily muscled food animals. Indeed, current research is underway to investigate and develop these potentialities. Sure enough, a large pharmaceutical company has recently applied for a patent on an antibody vaccination for the myostatin protein.

A medical doctor and author of weight training articles asserts that overexpression of myostatin is to blame for weight lifters that have trouble gaining muscle mass. The spokesperson for a supplement and testing lab erroneously implied that the "rarest" form of mutation in the myostatin gene is responsible for a top competitive bodybuilder&#8217;s massive muscle gains, not taking into account the performance-enhancement substances the bodybuilder may be using. The public media has, of course, predicted that "steroid-popping" athletes will take advantage of myostatin inhibitors to gain competitive edge (3).

Many of these assertions are unfounded or they misrepresent the science. Granted, the possibility exists that manipulation of the myostatin gene in humans may be a key to reversing muscle-wasting conditions. However, too little is still yet unknown regarding myostatin&#8217;s role in muscle growth regulation. It is imperative that research demonstrates that the loss of myostatin activity in adults can cause muscle tissue growth. Likewise, research must also prove that overexpression or administration of myostatin causes loss of muscle mass. Also important is to know if manipulation of myostatin will interfere with other growth systems, especially in other tissues, and result in abnormal pathologies. Although McPherron&#8217;s gene knockout mice did not experience any other gross abnormalities, mice are not humans.

We do not fully understand the roles of myostatin in exercise-induced muscle hypertrophy or regeneration following muscle injury. Until we do, it may be premature to blame the lack of hypertrophy in weightlifters on overexpression of myostatin. Nor does the research support the claim that a top bodybuilder&#8217;s muscle mass gains are resultant of a detected mutation in the myostatin gene. The research simply does not advocate blaming genetic myostatin variations as a source of significant differences in human phenotypes.

Considering the history of the athlete&#8217;s propensity, in the public eye, to abuse performance-enhancement substances, the media&#8217;s prediction of myostatin-inhibitor may or may not be warranted. We all know that today&#8217;s athletic arena demands gaining the competitive edge to maintain top level competition. For many athletes, that is accomplished by supplementing hard training with substances that enhance growth or performance. Whether or not myostatin inhibitors will be added to the arsenal of substances is difficult to predict. Until science reveals the full nature of this growth factor and its role in the complex regulation of muscle tissue, and researchers determine its therapeutic implications, we can only surmise. Despite attempts to tightly control any pharmaceutical uses of myostatin protein manipulation, they will likely surface at some point in the black market world of bodybuilding supplements. Let us hope that science has determined the side effects and the benefits by that point.

sprzedam biznes w calosci.

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Krótki zarys.

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o MGF juz bylo i ten sam rysunek szczura :-]
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Dzięki Nordland,starałem się powiązać artykuły,które udało mi sie znalesc na ten temat w jedną całośc.
Zdr.

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"Oddycham głęboko, stawiam piedestały. Jutro będe duży, dzisiaj jestem mały..."

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Już prawei rok temu bębnili o tym w "Science" - potem art "skopiowała" wyborcza w swoim dodatku nauka...
Ogólnie to czeka nas świetlana przyszłosć: megakoksy, ponadprzecietnie inteligentni ludzie, supersportowcy - to tak w skrócie

I'm the GOD

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niezły jest ten skoksowany chomik

Wracam :D

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Dzieki Seewy :)

Krzychu:To co napisałeś to jest prawda,bo tak ma niby sie stać,ale póki co brzmi to bardzo śmiesznie pomimo obiecujących prognoz.

Zainteresowałem sie tym niezmiernie choćby nawet ze względu na to jakim kosztem możemy otrzymać coś na co musielibyśmy pracować kupe czasu,a anabolizm miesniowy zwieksza sie ze źródeł naukowych po samym IGF 10xkrotnie bardziej niz po GH..Ciekawe co z reszta?
Bloker miostatyny też fajna sprawa..podrązę głębiej w temacie,może sie okaze jednak ze jest na rynku już coś co blokuje naszą MST ;] ..

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Widze, że dążysz do tego aby być pierwszym genetycznym mutantem w PL/UK

Swoją drogą decydowanie np. o losie nienarodzonego dziecka - wpływ na jego genom - taki jak włśnie zdolność pojmowiania, muskulatura czy chociażby kolor oczu to już zbyt przedmiotowe i niebezpieczne eksperymenty. Co prawda dzieki podobnym umiejętnościom będzie można wyeliminować ryzyko groźnych chorób, poprawic - jak SamuraI - swą muskulaturę, ale zawsze jest też ciemna strona medalu...

Zmieniony przez - krzychugod w dniu 2007-08-19 21:17:33

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Co do zbliżających się Igrzysk w Pekinie wklejam temat który już kiedyś zamieściłem:

Profesor Helga Pfeifer, niegdyś podejrzana o zbudowanie potęgi pływaków NRD na sterydach, zaraz po zburzeniu muru berlińskiego pojawiła się w Chinach jako współpracownica trenera chińskiej reprezentacji pływackiej. Po wpadce, po cichu zniknęła i została zapomniana, po około 10 latach znowu odnalazła się w Chinach u boku tego samego trenera by ponownie ZNIKNĄĆ, wraz z trenerem i pięćdziesiątką młodych utalentowanych chińskich pływaków.

Na otwarcie nowo powstałej pływalni olimpijskiej w Szanghaju zaproszono, samych VIP&#8217;ów oraz liczne grono dziennikarzy. Wśród nich była Grit Hartmann, która zwróciła uwagę na jedyną europejską twarz znajdującą się wśród oficjeli.
&#8222;Gdzieś już ją widziałam&#8221; &#8211; pomyślała Pani Hartmann, korespondentka gazety z Frankfurtu.

A było to 15 lat temu w lipskiej Akademii Wychowania Fizycznego i Sportu.
Helga Pfeifer, była członkiem kierownictwa utajnionego instytutu sportowego FKS Leipzig. Prowadziła tam pracownię pływania, prowadziła badania nad wydolnością organizmu i wkrótce uznano ją za jedną z twórców pływackiej potęgi NRD. Stała się specjalistką od wspomagania organizmu sterydami oraz takimi środkami, które nie znajdują się na liście zakazanych lub są niewykrywalne.
Po zburzeniu muru berlińskiego, w roku 1991 instytut został rozwiązany. Helga Pfeifer dostała na pożegnanie tytuł profesora i polecenie by znalazła sobie nowe zajęcie. Znalazła !
W 1992 roku, wraz z chińskimi trenerem pływania Zhou Mingiem, znalazła się w Szanghaju.
Od tego czasu, dziwnym trafem o Chińskim pływaniu stawało się coraz głośniej. Podczas Mistrzostw Świata w Rzymie w 1994 r. chińskie pływaczki były klasą same dla siebie.
Zdobyły 12 złotych medali.
Nie uszło to uwadze kontrolerów antydopingowych i mistrzynie świata z Rzymu zostały zdyskwalifikowane. Udowodniono im stosowanie anabolików. Winą za cały skandal obarczono trenera Zhou Minga, wyrzucono go ze związku i odsunięto od sportu. Helga Pfeifer po cichu opuściła Chiny.

Jesienią 2003 roku, trener Zhou Ming, ponownie zaczął pojawiać się na Chińskich pływalniach wraz z żoną, specjalistką od naboru i selekcji utalentowanej młodzieży. Przeprowadził testy w kilku prowincjach. Ich efektem było stworzenie stuosobowej grupy młodych super talentów. Specjalnie na zbliżające się pekińskie Igrzyska. Świat wiedział o tych testach ale dopiero pojawienie się profesor Pfeifer wzbudziło podejrzenia.
Na konferencji prasowej po otwarciu pływalni Grit Hartmann po prostu zapytała rzecznika prasowo chińskiego związku pływackiego, co robi w Szanghaju profesor Helga Pfeifer.
Odpowiedź brzmiała: &#8222;Pani profesor jest gościem związku&#8221;. Grit Hartmann nie odpuszczała kolejne pytanie postawiła zaczepnie, czy wiadomo co w przeszłości robiła Pfeifer, w odpowiedzi otrzymała zdanie &#8222;To nas nie interesuje&#8221;.
Wieść o ponownym pobycie Pfeifer w Chinach wywołała ogromne poruszenie. Prezes Światowego Związku Zawodowego Trenerów Pływackich, zwrócił się do Pekinu z oficjalną prośbą o wyjaśnienie tej sprawy. Odpowiedź nie nadeszła, ale rzecznik narodowego komitetu kontroli antydopingowej w Chinach Zhao Jian przyznał, że sprawa jest badana.
Australijskie pływaczki poinformowały o zaistniałej sytuacji Agencję Antydopingową WADA. A John Leonard, przewodniczący Związku trenerów w USA, osobiście wybrał się do Chin, by odbyć rozmowę z trenerem Zhou Mingiem. Niestety nie potrafił go odnaleźć. Rozłożono ręce w Chińskim Związku Pływackim i Nardowym Komitecie Olimpijskiem. Nie potrafiono mu pomóc w Ministerstwie Sportu i Biurze Organizacyjnym Olimpiady 2008 r.
Nie mogąc znaleźć trenera Minga, Leonard zdecydował się odszukać setkę super talentów wyselekcjonowanych przez niego przed dwoma laty. I tu czekało kolejne rozczarowanie, ponieważ w pewnej szkole mistrzostwa sportowego odnalazł tylko...połowę z nich.
&#8222;Żaden z chińskich trenerów nie wierzył żeby 50 potencjalnych medalistów ulotniło się jak kamfora. Albo istotnie nic nie wiedzą albo nie chcą powiedzieć&#8221; &#8211; mówi John Leonard.
John Leonard twierdzi, że zaangażowano Zhou Minga z pełną premedytacją i świadomością. Oddano mu do dyspozycji 50 młodych talentów, które w ukryciu przed Światem sposobione są do Igrzysk, z pomocą wiedzy profesor Pfeifer. Prawdopodobnie młodzi pływacy przetestują pod jej okiem najnowsze zdobycze dopingowe, zapewne z manipulacjami genetycznymi włącznie. I pojawią się na pływalniach w odpowiednim momencie, na około pół roku przed Olimpiadą, gdy doping będzie już odstawiony a co za tym idzie bardzo trudny do wykrycia.
Chiny intensywnie przygotowują się do Igrzysk w Pekinie. Powstał tzw. &#8222;Plan 200&#8221; &#8211; zakładający zdobycie za 3 lata co najmniej 200 medali olimpijskich w wybranych, indywidualnych konkurencjach.
Zakłada się, iż gdzieś w ukryciu trener Zhou Ming i Helga Pfeifer, tworzą grupę idealnych, nastawionych tylko na zwycięstwo, genetycznych mutantów. Niestety brak wyżej wymienionych osób, warunkuje także absolutny brak dowodów, wszystko do tej pory to tylko spekulacje bez żadnego prawa dowodowego. A Pekin chce medali, &#8222;Lud woła o medale&#8221;. Bo przecież po to organizuje się igrzyska u siebie.



Na podstawie: &#8222;Polityka&#8221; nr 23 (2507), 11 czerwca 2005, cena 4,50 zł i Internetu.

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