Steroidal SARM. Not much data for it. Just one paper so far:
J Biol Chem. 2010 May 28;285(22):17054-64. Epub 2010 Mar 31.
Discovery of the selective androgen receptor modulator MK-0773 using a rational development strategy based on differential transcriptional requirements for androgenic anabolism versus reproductive physiology.
Schmidt A, Kimmel DB, Bai C, Scafonas A, Rutledge S, Vogel RL, McElwee-Witmer S, Chen F, Nantermet PV, Kasparcova V, Leu CT, Zhang HZ, Duggan ME, Gentile MA, Hodor P, Pennypacker B, Masarachia P, Opas EE, Adamski SA, Cusick TE, Wang J, Mitchell HJ, Kim Y, Prueksaritanont T, Perkins JJ, Meissner RS, Hartman GD, Freedman LP, Harada S, Ray WJ.
Department of Molecular Endocrinology, Merck Research Laboratories, West Point, Pennsylvania 19486, USA.
Abstract
Selective androgen receptor modulators (SARMs) are androgen receptor (AR) ligands that induce anabolism while having reduced effects in reproductive tissues. In various experimental contexts SARMs fully activate, partially activate, or even antagonize the AR, but how these complex activities translate into tissue selectivity is not known. Here, we probed receptor function using >1000 synthetic AR ligands. These compounds produced a spectrum of activities in each assay ranging from 0 to 100% of maximal response. By testing different classes of compounds in ovariectomized rats, we established that ligands that transactivated a model promoter 40-80% of an agonist, recruited the coactivator GRIP-1 <15%, and stabilized the N-/C-terminal interdomain interaction <7% induced bone formation with reduced effects in the uterus and in sebaceous glands. Using these criteria, multiple SARMs were synthesized including MK-0773, a 4-aza-steroid that exhibited tissue selectivity in humans. Thus, AR activated to moderate levels due to reduced cofactor recruitment, and N-/C-terminal interactions produce a fully anabolic response, whereas more complete receptor activation is required for reproductive effects. This bimodal activation provides a molecular basis for the development of SARMs.
PMID: 20356837 [PubMed - indexed for MEDLINE]PMCID: PMC2878020 [Available on 2011/5/28]