Effects of androgen on alpha- and beta-adrenergic receptors in membranes from the rat seminal vesicle.
The effects of castration and androgen-replacement on adrenergic receptors in membranes from the rat seminal vesicle were studied. Membranes from seminal vesicles showed saturable and high-affinity binding sites for the beta-adrenergic receptor antagonist, [3H]dihydroalprenolol ([3H]DHA), and the alpha 1-adrenergic receptor antagonist, [3H]prazosin. Castration markedly reduced beta-adrenergic receptors with decreasing the effect of GTP modulating the receptor-ligand affinity, suggesting defects in both the receptor per se and the guanine-nucleotides-regulating mechanism after castration. In contrast, castration increased alpha 1-adrenergic receptors and androgen-replacement reversed this change. The effects of GTP decreasing the alpha 1-receptor binding affinity to the radioligand were observed to a similar extent in the castrated and control membranes. These results demonstrate an inverse regulation by androgen on beta- and alpha 1-adrenergic receptors in membranes of the rat seminal vesicle.
Shima
S
S
Department of Biochemistry, St. Marianna University School of Medicine, Kanagawa, Japan.
D000728:Androgens / Q000494:pharmacology*; D000818:Animals; D001665:Binding Sites; D002369:Castration; D004082:Dihydroalprenolol / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D008297:Male; D008566:Membranes / Q000187:drug effects; D011224:Prazosin / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011942:Receptors, Adrenergic, alpha / Q000737:chemistry / Q000187:drug effects*; D011943:Receptors, Adrenergic, beta / Q000737:chemistry / Q000187:drug effects*; D012669:Seminal Vesicles / Q000187:drug effects* / Q000378:metabolism
D000728:Androgens; D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D004082:Dihydroalprenolol; D011224:Prazosin