Preservation of endothelium-dependent vascular relaxation in cholesterol-fed rabbit by treatment with the calcium blocker PN 200110.
We tested the effects of low doses of a dihydropyridine calcium antagonist, PN 200110, on endothelium-dependent vascular relaxation in rabbits fed a 1% cholesterol diet. The drug was given orally, 1 mg/day, and control rabbits received placebo. Plasma total cholesterol after 10 weeks, was similar in the placebo- and PN 200110-treated groups. The respective values averaged 2140 +/- 116 (n = 14; mean +/- SEM) and 2012 +/- 115 mg/dl (n = 13). In placebo-treated rabbits, sudanophilic aortic lesions covered 52 +/- 5% of the intimal surface, and the aortic cholesterol concentration was 72 +/- 6 mg/g protein. Corresponding values in aortas from PN 200110-treated rabbits were significantly lower [36 +/- 5% (P less than 0.03) and 52 +/- 3 mg/g protein (P less than 0.03)]. Maximal endothelium-dependent cholinergic relaxation of aortic strips in untreated (n = 14) and treated cholesterol-fed rabbits (n = 13) differed significantly (P less than 0.01) and averaged 31 +/- 4% and 61 +/- 7% of the value in normocholesterolemic controls (n = 13). We conclude that cholesterol feeding suppresses endothelium-dependent relaxation evoked by acetylcholine, and that PN 200110 reduces the severity of atherosclerosis and impairment of endothelium-dependent relaxation.
D000818:Animals; D001011:Aorta / Q000187:drug effects; D001161:Arteriosclerosis / Q000503:physiopathology; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D002791:Cholesterol, Dietary / Q000008:administration & dosage*; D004727:Endothelium / Q000187:drug effects / Q000648:ultrastructure; D006439:Hemodynamics / Q000187:drug effects; D017275:Isradipine; D008297:Male; D008855:Microscopy, Electron, Scanning; D010069:Oxadiazoles / Q000494:pharmacology*; D010275:Parasympathetic Nervous System / Q000187:drug effects; D011817:Rabbits
D002121:Calcium Channel Blockers; D002791:Cholesterol, Dietary; D010069:Oxadiazoles; D017275:Isradipine