Vascular responses to sodium arachidonate in experimental hypertension.
This study characterizes vascular responsiveness to sodium arachidonate (C 20:4) in four models of hypertension [deoxycorticosterone acetate (DOCA) hypertensive rats, two kidney-one clip (2K-1C) renal hypertensive rats, spontaneously hypertensive rats (SHR), and psychosocial hypertensive mice]. Isolated arterial strips (aorta, mesenteric artery, tail artery) were equilibrated under optimal resting tension in physiological salt solution for measurement of isometric force generation. Dose-response curves to arachidonate (10(-10) to 10(-4) g/ml) in arteries from DOCA and 2K-1C hypertensive rats were shifted to the left compared to those in arteries from control rats. In arteries from SHR and psychosocial hypertensive mice, the dose-response relationships were unchanged compared to normotensive values. Arteries from DOCA hypertensive and 2K-1C hypertensive rats developed greater maximal contractile responses to arachidonate than controls; maximal responses in arteries from SHR and psychosocial hypertensive mice were unchanged compared to normotensive values. Contractions to arachidonate were inhibited by indomethacin (0.5 and 5 micrograms/ml) and by aspirin (5 and 50 micrograms/ml). The fatty acid, oleate (C 18:1), had no effect on the contractile state of the arteries, whereas prostaglandin F2 alpha caused contraction. These results indicate altered responsiveness to exogenous arachidonate in arteries from DOCA and 2K-1C hypertensive rats, but not in arteries from SHR and psychosocial hypertensive mice.
D000818:Animals; D001011:Aorta / Q000187:drug effects; D001095:Arachidonic Acids / Q000494:pharmacology* / Q000627:therapeutic use; D001158:Arteries / Q000187:drug effects; D001808:Blood Vessels / Q000187:drug effects*; D003900:Desoxycorticosterone / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006973:Hypertension / Q000188:drug therapy*; D006977:Hypertension, Renal / Q000188:drug therapy; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects; D051379:Mice; D008808:Mice, Inbred CBA; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D051381:Rats; D011918:Rats, Inbred SHR; D011919:Rats, Inbred Strains
D001095:Arachidonic Acids; D003900:Desoxycorticosterone