Receptor binding of allylestrenol, a progestagen of the 19-nortestosterone series without androgenic properties.
Allylestrenol (17 alpha-allyl-17 beta-hydroxy-4-estren) is an orally active progestagen of the 19-nortestosterone series resembling progesterone since it has no detectable androgenic activity in animal studies and in the human. In the present study, the affinity of its 3-keto metabolite for the transformed progesterone receptor in intact MCF-7 cells was about twice that of progesterone and cyproterone acetate and about 2-3 times less than that of medroxyprogesterone acetate and norethisterone, reflecting the known progestational activity of allylestrenol. The affinity of 3-ketoallylestrenol for the transformed androgen receptor in intact MCF-7 cells was weak (like other progestagens lacking androgenic activity or possessing anti-androgenic activity) and lower than that of weakly androgenic progestagens. On the other hand, the relatively high affinity of 3-keto-allylestrenol for the non-transformed androgen receptor at 4 degrees C in the cytosol fraction did not reflect the known lack of androgenic activity of allylestrenol. Thus competitive studies carried out with transformed receptor complexes in intact cells at 37 degrees C and non-transformed complexes in cytosol distinguish progestagen with weak androgenic activity (e.g. norethisterone) from those displaying no androgenic activity or possessing anti-androgenic activity (e.g. 3-keto-allylestrenol, progesterone, cyproterone acetate and spironolactone).
D000500:Allylestrenol / Q000378:metabolism*; D000818:Animals; D001667:Binding, Competitive; D001943:Breast Neoplasms; D002352:Carrier Proteins / Q000378:metabolism; D002460:Cell Line; D004963:Estrenes / Q000378:metabolism*; D005260:Female; D006801:Humans; D007700:Kinetics; D009215:Myometrium / Q000378:metabolism; D011817:Rabbits; D011944:Receptors, Androgen / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000378:metabolism*; D011965:Receptors, Glucocorticoid / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism*; D011987:Receptors, Steroid / Q000378:metabolism*; D012738:Sex Hormone-Binding Globulin
D002352:Carrier Proteins; D004963:Estrenes; D011944:Receptors, Androgen; D011960:Receptors, Estrogen; D011965:Receptors, Glucocorticoid; D011980:Receptors, Progesterone; D011987:Receptors, Steroid; D012738:Sex Hormone-Binding Globulin; D000500:Allylestrenol