Anthony Roberts
Selective Androgen Receptor Modulators (SARMs) provide the benefits of traditional anabolic/androgenic steroids such as testosterone (including increased muscle mass, fat loss, and bone density), while showing a lower tendency to produce unwanted side effects. They are a unique class of molecules currently under development for treatment of a variety of diseases that were previously treated with anabolic steroids and other medications. SARMs have been studied and developed since 1998, and as of this writing (2009) it should be stated that they are still very much in the infancy of their development and marketing.
Briefly and simply stated, the Androgen Receptor (AR) is the cellular receptor that androgens (like testosterone and other anabolic steroids) bind to. This bound androgen/receptor then combine with another similar combination (usually another androgen/androgen-receptor pair), and travel to the cell’s nucleus, where gene transcription is induced. This is one known mechanism of how androgens such as anabolic steroids exert their effects on cells. SARMs have the potential to take the place of the androgen, for all practical intents and purposes, and therefore exert many of the same positive effects on muscle tissue as anabolic steroids (such as testosterone).
The Androgen Receptor plays a critical role in the development and function of primary and accessory sexual organs, skeletal muscle, and bone, as well as several other organs. When Selective Androgen Receptor Modulators bind to the receptor, they demonstrate anabolic (hypertrophic) activity in both muscle and bone, making them ideal candidates for androgen replacement therapy, muscle wasting, and treating Osteoporosis. In theory, they bind to the receptor and place it in a conformation that is significantly different than typical androgen receptors stimulators (such as steroids), and therefore are able to alter the gene-transcription process in a manner that is tissue specific.
It is this specificity that makes these receptor modulators able to selectively cause muscle growth, while reducing or eliminating unwanted secondary effects.
Ergo, unlike anabolic steroids, SARMs generally produce fewer unwanted side effects on non-target tissues such as the prostate, hairline, sebaceous glands, and secondary sexual organs. Some SARMs have even been developed specifically for the treatment of those kinds of side effects (i.e. for benign prostate hypertrophy).
Current oral androgen replacement therapy is very limited, with the only available forms of testosterone being Andriol (which is widely seen as expensive and ineffective) and Methyltestosterone (which is liver toxic). SARMs represent an alternative to the currently available oral testosterone preparations, and offer the user molecules that exhibit high oral bioavailability without the liver toxicity.
Although these molecules are tissue-selective with regards to their effects, they are not perfectly tissue-selective. Some display a disparity of anabolic (*tissue building) versus androgenic (*secondary sexual characteristic promoting) effect as high as 10:1 (although it should be noted that some have a much lower ratio). In practical terms, it would be highly unlikely that an effective muscle building dose would cause any noticeable side effects, and especially not when compared to traditionally prescribed anabolic steroids such as testosterone.
At this stage of development there are no SARMs available on the legitimate pharmaceutical market, although one (Ostarine) has made it into the third and last phase of clinical development (and is available on the black market, in liquid “research” form, from one supplier within the United States. Unfortunately, at this early stage of development, the exact mechanisms of their tissue selective activity is not entirely understood, nor is the full scope of their pharmacokinetic and pharmacodynamic activity.
There are numerous SARMs currently in the developmental stage with varying degrees of anabolic and androgenic activity, and varying potential for side effects. In general, though, the majority of them produce few side effects and have anabolic ratings similar to testosterone.
They typically display high oral bioavailability, and therefore most SARMs under development are going to eventually enter the market as oral medications. .
Although they have been banned for the past few years by the World Anti-Doping Agency, and there have been efforts underway to develop a testing protocol for them, there is currently no accepted testing procedure in place. The relatively short half life of SARMs, the uniqueness of their structure, their effectiveness, and the fact that research into their development is still in its infancy, presents a new and novel problem for doping authorities everywhere.
http://www.sarmssearch.com/?gclid=CNPTuZu8xqECFQP7agodqipxAAPrevod ------
Selektivni modulatori androgenih receptora (SARMs) pružaju prednosti tradicionalnih anaboličkih / androgenim steroidima kao što su testosteron (uključujući i povećanje mišićne mase, gubitak masnoće, gustoće kostiju i), dok je prikazano niže tendenciju proizvesti neželjene nuspojave. Oni su jedinstveni klasa molekula trenutno u razvoju za liječenje raznih bolesti koje su prethodno bile tretirane anaboličkih steroida i drugih lijekova. SARMs proučen i razvija od 1998, a od ovog pisanja (2009) to bi trebalo biti navedeno da su još uvijek jako puno u začetku njihova razvoja i marketinga.
Kratko i jednostavno rečeno, androgenih receptora (AR) je stanični receptor koji androgena (testosterona i ostalih poput anaboličkih steroida) vežu. Ovaj vezana androgena / receptore onda kombiniraju s drugim sličnim kombinaciju (obično drugi androgena / androgenih receptora par), i putuju na ćeliju jezgre, gdje je inducirani transkripciju gena. Ovo je jedan poznati mehanizam kako androgena kao što su anabolički steroidi djeluju njihove učinke na stanice. SARMs imaju potencijal da se mjesto androgena, za sve praktične namjere i svrhe, i time vrše mnoge od iste pozitivne učinke na mišićno tkivo kao anaboličkih steroida (npr. testosterona).
Androgenih receptora igra ključnu ulogu u razvoju i funkciji osnovne i dodatne opreme spolne organe, skeletnih mišića i kosti, kao i nekoliko drugih organa. Kad Selektivni modulatori androgenih receptora vežu za receptore, što ukazuju na anabolički (hipertrofička) aktivnosti u oba mišića i kostiju, što ih čini idealnim kandidatima za androgena zamjensku terapiju, mišića gubit, i liječenje osteoporoze. U teoriji, oni se vežu za receptore i stavite ga u konformaciju koja je bitno drugačiji od tipičnih androgenih receptora stimulatora (poput steroida), i stoga su u stanju izmijeniti gena transkripcija-procesa na način koji je specifičan tkiva.
Upravo ta specifičnost koja čini tih receptora modulatori u mogućnosti selektivno uzrokovati rast mišića, dok je smanjenje ili uklanjanje neželjene sekundarne posljedice.
Ergo, za razliku od anabolic steroidi, SARMs uglavnom proizvode manje neželjenih nuspojava na ne-ciljne tkiva kao što su prostate, kose, lojnih žlijezda i sekundarnih spolnih organa. Neki čak SARMs razvijene su posebno za liječenje one vrste nuspojava (npr. za benigni prostate hipertrofijom).
Trenutni usmeni androgena nadomjesna terapija je vrlo ograničena, uz samo nekoliko dostupnih načina testosterona se Andriol (što mnogi smatraju skup i neučinkovit) i Methyltestosterone (koji je otrovan jetre). SARMs predstavljaju alternativu za testosteron trenutno dostupne oralne pripreme, te nude upute za molekule koje pokazuju visoku bioraspoloživost usmeni bez toksičnost jetre.
Iako se te molekule tkiva-selektivni s obzirom na njihove učinke, oni nisu savršeno tkiva-selektivni. Neki prikaz razlike anaboličkih (* tkiva zgrada) prema androgenim (* sekundarne spolne karakteristike promicanje) učinak kao visok kao 10:01 (iako treba napomenuti da neke imaju puno niže omjer). U praktičnom smislu, to bi bilo malo vjerojatno da na snazi mišića zgrade doze bi uzrokovati nikakve vidljive nuspojave, a posebno ne u odnosu na tradicionalno propisanim anaboličke steroide, kao što su testosteron.
U ovoj fazi razvoja nema SARMs dostupne na legitimne farmaceutskog tržišta, iako je jedan (Ostarine) je bilo je na trećoj i posljednjoj fazi kliničkog razvoja (i dostupan je na crnom tržištu, u tekućim "istraživanje" obliku, iz jednog dobavljača u Sjedinjenim Državama. Nažalost, u ovoj ranoj fazi razvoja, točno mehanizmi njihova tkiva selektivna aktivnost nije u potpunosti shvatio, niti je pun opseg svojih farmakokinetike i farmakodinamika aktivnosti.
Postoje brojne SARMs trenutno u fazi razvoja s različitim stupnjevima anaboličkih i androgenim aktivnosti, i različitog potencijala za nuspojave. Općenito, ipak, većina ih je proizvesti nekoliko nuspojava i imaju anabolički ocjene slične testosterona.
Oni su obično pokazuju visoku bioraspoloživost usmeni, pa većina SARMs u razvoju će na kraju ući na tržište kao oralni lijekovi. .
Iako su zabranjene u proteklih nekoliko godina od strane Svjetske antidoping agencije, a tu su u tijeku napori da razvije testiranje protokola za njih, trenutno ne postoji prihvaćena postupak ispitivanja na mjestu. Relativno kratak polovina života od SARMs, jedinstvenost njihove strukture, njihove učinkovitosti, kao i činjenica da istraživanja u njihov razvoj je još uvijek u povojima, predstavlja novi i novi problem za dopinga tijela posvuda.
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