Endothelium-dependent and independent relaxation of aortic rings from hypertensive rats.
The relaxation effects of endothelium-dependent (acetylcholine, histamine) and endothelium-independent (nitroprusside, nitrite) relaxing substances were comparatively examined on contracted thoracic aortic rings from normotensive and experimental renal and desoxycorticosterone acetate (DOCA)-salt hypertensive Wistar rats. On the aorta preparations from hypertensive animals a highly significant depression of the maximal relaxation effect of histamine and acetylcholine was observed. This was not seen with nitroprusside and nitrite. By use of a bioassay technique it was demonstrated that the depression of the endothelium-mediated response is not due to a diminished release of endothelium-derived relaxing factor. Impaired coupling between the endothelium and the smooth muscle cells is suggested to be responsible for that depression.
Van de Voorde
J
J
Leusen
I
I
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects / Q000503:physiopathology*; D003900:Desoxycorticosterone; D015237:Dinoprost; D004727:Endothelium / Q000378:metabolism / Q000503:physiopathology; D006632:Histamine / Q000494:pharmacology; D006973:Hypertension / Q000139:chemically induced / Q000378:metabolism / Q000503:physiopathology*; D066298:In Vitro Techniques; D008026:Ligation; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation; D009131:Muscle, Smooth, Vascular / Q000503:physiopathology; D009599:Nitroprusside / Q000494:pharmacology; D011460:Prostaglandins F / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012077:Renal Artery; D012965:Sodium Chloride; D012977:Sodium Nitrite / Q000494:pharmacology
D011460:Prostaglandins F; D009599:Nitroprusside; D003900:Desoxycorticosterone; D012965:Sodium Chloride; D006632:Histamine; D015237:Dinoprost; D012977:Sodium Nitrite; D000109:Acetylcholine