title: Cimetidine, a histamine H2 receptor antagonist, occupies androgen receptors.
abstract: The histamine H2 receptor antagonist cimetidine is in increasing usage in the medical management of peptic ulcer. In clinical trials, its most frequent side effect is gynecomastia. Such estrogenic/antiandrogenic manifestations are well known side effects of treatment with digitoxin or spirolactones. Both of these drugs share a common skeleton with the steroid hormones and have been shown to occupy estrogen and/or androgen receptors. Cimetidine has no measurable affinity for rat uterine estradiol receptors, but competes for tritiated dihydrotestosterone-binding sites in mouse kidney preparations with a displacement curve parallel to that for unlabeled dihydrotestosterone. Steroid receptor-mediated side effects, therefore, may not be confined to molecules with a common skeleton, such as steroids, spirolactones, and cardiac glycosides, but may extend to such apparently unrelated molecules as histamine antagonists and androgens.
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D002927:Cimetidine / Q000378:metabolism*; D013196:Dihydrotestosterone / Q000494:pharmacology; D005260:Female; D006146:Guanidines / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism; D007700:Kinetics; D008297:Male; D051379:Mice; D011944:Receptors, Androgen / Q000187:drug effects / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000378:metabolism; D011968:Receptors, Histamine; D011970:Receptors, Histamine H2; D011987:Receptors, Steroid / Q000378:metabolism*; D014599:Uterus / Q000378:metabolism
chemical_list: D006146:Guanidines; D011944:Receptors, Androgen; D011960:Receptors, Estrogen; D011968:Receptors, Histamine; D011970:Receptors, Histamine H2; D011987:Receptors, Steroid; D013196:Dihydrotestosterone; D002927:Cimetidine