castrated

S-23 ((S)-3-(4-chloro-3-fluorophenoxy)-N-(4-cyano-3-(trifluoromethyl)phenyl)-2-hydroxy-2-methylpropanamide) is an oral selective androgen receptor modulator (SARM) with a Ki of 1.7 nM. S-23 increases prostate, seminal vesicle, and levator ani muscle weights in castrated rats.

Topterone (Win 17,665) is a potent topical antiandrogen that inhibits the stimulation of lumbar organ development by testosterone and dihydrotestosterone in castrated immature male hamsters.

Bornaprolol (FM-24) is a β-adrenoceptor antagonist that significantly reduces plasma levels of luteinizing hormone (LH) in castrated rat models. It is applicable in research related to cardiovascular diseases such as hypertension and angina.

Abarelix acetate is a synthetic third generation gonadotropin-releasing hormone receptor (GnRHR) antagonist. It increases histamine release from rat peritoneal mast cells in vitro and from a human skin model ex vivo. In vivo, abarelix decreases plasma luteinizing hormone (LH) levels six hours post-treatment in castrated rats, with levels returning to baseline within 24 hours.3 Abarelix (2 mg/kg) also transiently decreases plasma testosterone levels in intact rats, with levels returning to baseline within seven days post-treatment. Formulations containing abarelix have previously been used in the treatment of advanced prostate cancer.

NBI-42902 is a potent inhibitor of peptide radioligand binding to the human GnRH receptor (K(i) = 0.56 nm). Tritiated NBI-42902 binds with high affinity (K(d) = 0.19 nm) to a single class of binding sites and can be displaced by a range of peptide and nonpeptide GnRH receptor ligands. In vitro experiments demonstrate that NBI-42902 is a potent functional, competitive antagonist of GnRH stimulated IP accumulation, Ca(2+) flux, and ERK1/2 activation. It did not stimulate histamine release from rat peritoneal mast cells. Finally, it is effective in lowering serum LH in castrated male macaques after oral administration. Overall, these data provide a benchmark of pharmacological characteristics required for a nonpeptide GnRH antagonist to effectively suppress gonadotropins in humans and suggest that NBI-42902 may have clinical utility as an oral agent for suppression of the hypothalamic-pituitary-gonadal axis. (source: Endocrinology. 2007 Feb;148(2):857-67. Epub 2006 Nov 9.)

Myricanone has antioxidant, and anticancer activities, it has apoptosis-promoting ability by triggering caspase activation, and suppression of cell proliferation by down-regulation of NF-κB and STAT3 signalling cascades. Myricanone shows in vitro testost