Increased Oxygen Consumption in Cholesterol-Fed Rabbits

Abstract

Aortic walls from animals with diet-induced atherosclerosis have increased oxidative capacities for various substrates (1–3) and mitochondria isolated from atherosclerotic rabbit aortae have increased respiratory rates (4). Atherogenic diets produce multiple systemic disturbances and metabolic changes in the wall of atherosclerotic arteries have been shown to occur in other organs (5–7). As atherosclerosis of the coronary arteries may critically limit the oxygen supply of the heart it would appear important to determine whether oxidative metabolism and oxygen requirements of the myocardium are increased under dietary conditions that promote atherogenesis. To explore whether atherosclerosis induced by a high cholesterol diet is associated with an increase in systemic or myocardial oxidative metabolism, the basal oxygen consumption of cholesterol-fed rabbits and the oxygen uptake of the isolated hearts from these animals were measured.