17Beta-estradiol alters isoproterenol-induced relaxation in rat aortic rings.
Female Wistar rats were treated with 17beta-estradiol (E2) (10 microg, s.c.) or with sesame oil for 3 days. The relaxation induced by isoproterenol (10(-9)-3 x 10(-6) M) in aortae precontracted with norepinephrine was significantly suppressed in aortae from E2-treated rats compared with the relaxation in those from control rats. N(G)-Nitro-L-arginine, a nitric oxide synthase inhibitor, inhibited isoproterenol-induced relaxation in aortae from both E2-treated and control rats. Metyrapone, a cytochrome P-450 monooxygenase inhibitor, inhibited it in aortae from control rats, but metyrapone enhanced the maximum relaxation in aortae from E2-treated rats. These results suggest that E2 modulates isoproterenol-induced vasodilation through nitric oxide and cytochrome P-450-dependent metabolites.
Honda
H
H
Department of Pharmacology, Tokyo University of Pharmacy and Life Science, Hachioji, Japan.
Yamaguchi
K
K
Kogo
H
H
D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects* / Q000502:physiology; D001993:Bronchodilator Agents / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D007545:Isoproterenol / Q000494:pharmacology*; D008797:Metyrapone / Q000494:pharmacology; D019335:Nitroarginine / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D012715:Sesame Oil / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects*
D001993:Bronchodilator Agents; D004791:Enzyme Inhibitors; D019335:Nitroarginine; D004958:Estradiol; D012715:Sesame Oil; D007545:Isoproterenol; D008797:Metyrapone