Vasodilator effects of clonidine on the mesenteric arterial beds in normotensive and spontaneously hypertensive rats.
Clonidine, an alpha 2-agonist, caused a concentration-dependent vasodilation of the mesenteric arterial beds in both normotensive and hypertensive rats. The clonidine-induced vasodilation was inhibited by NG-nitro-L-arginine, and the inhibition was reversed by L-arginine. The concentration-dependent vasodilation was not significantly different between normotensive and hypertensive rats. These results suggest that clonidine has an endothelium-dependent vasorelaxant action in the resistance artery such as rat mesenteric arterial bed, and the endothelium-dependent vasodilator effects of clonidine in the mesentery may be involved in the depressor effect of the drug.
Kamata
K
K
Department of Physiology and Morphology, Hoshi University, Tokyo, Japan.
Numazawa
T
T
Kasuya
Y
Y
D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D001794:Blood Pressure / Q000502:physiology; D003000:Clonidine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000502:physiology; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D019335:Nitroarginine; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D014664:Vasodilation / Q000502:physiology*
D019335:Nitroarginine; D001120:Arginine; D003000:Clonidine