Sodium nitroprusside-induced cGMP-independent vasodilator responses in the perfused rabbit ovarian vascular bed.
Sodium nitroprusside (SNP) (10(-9)-10(-6) mol) and carbachol (10(-9)-10(-6) mol) induced dose-dependent vasodilatation in the perfused rabbit isolated ovarian vascular bed. Carbachol, but not SNP-induced vasodilatation was abolished by treatment with CHAPS (4. 7 mg ml-1, 30 s) to remove the endothelium. Carbachol-induced responses were also significantly attenuated by LY 83583 (10(-5) M) and methylene blue (3x10(-5) M). L-NOARG (10(-5) M) reduced carbachol-induced vasodilatation. None of these compounds affected SNP-induced vasodilator responses. Both SNP- and carbachol-induced vasodilatation were attenuated by raising the [K+] in the Krebs' solution to 40 mM. The responses were also reduced by TEA (20 mM) but not by glibenclamide. It was therefore concluded that SNP induced cGMP-independent vasodilator responses in the perfused rabbit ovarian vascular bed. This vasodilator response involved membrane hyperpolarisation since it was lost in high [K+] Krebs' solution. (c) 1998 The Italian Pharmacological Society.
Yousif
M H
MH
Department of Pharmacology, Faculty of Medicine, Kuwait University, Safat, 13110, Kuwait.
Oriowo
M A
MA
Williams
K I
KI
D000634:Aminoquinolines / Q000494:pharmacology; D000818:Animals; D002217:Carbachol / Q000494:pharmacology*; D006152:Cyclic GMP / Q000502:physiology; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D006162:Guanylate Cyclase / Q000037:antagonists & inhibitors; D066298:In Vitro Techniques; D008751:Methylene Blue / Q000494:pharmacology; D009569:Nitric Oxide / Q000494:pharmacology*; D020030:Nitric Oxide Donors / Q000494:pharmacology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D052250:Nitric Oxide Synthase Type III; D019335:Nitroarginine / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology*; D010053:Ovary / Q000098:blood supply / Q000187:drug effects*; D011817:Rabbits; D014664:Vasodilation
D000634:Aminoquinolines; D004791:Enzyme Inhibitors; D020030:Nitric Oxide Donors; D009599:Nitroprusside; D019335:Nitroarginine; D009569:Nitric Oxide; D002217:Carbachol; C041715:6-anilino-5,8-quinolinedione; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; D006162:Guanylate Cyclase; D006152:Cyclic GMP; D008751:Methylene Blue