Effects of probucol on hypercholesterolemia-induced changes in antioxidant enzymes.
Effects of high cholesterol diet (0.5% and 1%) on the activity of antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px)] in the aortic tissue of rabbits were investigated in the absence or presence of probucol (0.5 gm/kg daily, orally). Five groups of ten rabbits each were studied. Group I, regular rabbit chow diet; Group II, chow + 0.5% cholesterol; Group III, chow + 0.5% cholesterol+probucol; Group IV, chow + 1% cholesterol and Group V, chow + 1% cholesterol+probucol. The aorta was removed at the end of 4 months for measurement of the antioxidant enzymes. An increase in activity of aortic antioxidant enzymes was noted in cholesterol-fed rabbits (Groups II and IV), being similar for SOD and catalase but higher for GSH-Px in Group IV as compared to Group II. Probucol was ineffective in altering this cholesterol-induced increase in enzyme activity except in Group III where it increased the activity of GSH-Px. These results suggest that aortic antioxidant enzymes are affected in hypercholesterolemia and that probucol is ineffective in altering the aortic antioxidant enzyme activity except GSH-Px activity which increased in 0.5% cholesterol-fed rabbits. The protective effects of probucol against hypercholesterolemic atherosclerosis may be partly due to an increase in the GSH-Px activity at low levels of hypercholesterolemia. At higher levels of hypercholesterolemia, the protective effects of probucol could be due to its antioxidant activity.
Mantha
S V
SV
Department of Physiology, College of Medicine, University of Saskatchewan, Saskatoon, Canada.
Kalra
J
J
Prasad
K
K
D000818:Animals; D000924:Anticholesteremic Agents / Q000494:pharmacology*; D001011:Aorta / Q000201:enzymology; D002374:Catalase / Q000378:metabolism; D002791:Cholesterol, Dietary / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D005979:Glutathione Peroxidase / Q000378:metabolism; D006937:Hypercholesterolemia / Q000188:drug therapy* / Q000201:enzymology* / Q000209:etiology; D011341:Probucol / Q000494:pharmacology*; D011817:Rabbits; D013482:Superoxide Dismutase / Q000378:metabolism
D000924:Anticholesteremic Agents; D002791:Cholesterol, Dietary; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D011341:Probucol