title: Carnitine ester hydrolysis in arteries from normal and cholesterol-fed rabbits and the effects of carnitine esters on arterial microsomal ACAT.
abstract: Carnitine ester hydrolysis was observed in homogenates of normal rabbit (Oryctolagus cuniculus) aortas and in intact aortas from normal and cholesterol-fed rabbits using [14C]palmitoylcarnitine as a substrate. Hydrolytic activity was decreased approximately 50% in arterial tissue from cholesterol-fed rabbits and may account for the observation that carnitine esters accumulate in arteries of animals fed atherogenic diets. Long-chain acylcarnitines (C14-C18) were found to be moderate inhibitors of microsomal acylCoA:cholesterol acyltransferase (ACAT, EC 2.3.1.26); short-chain acylcarnitine (C2-C10) and carnitine itself were not inhibitors. The data suggest that the increase in activity of arterial ACAT that characteristically parallels the development of atherosclerosis does not occur as a result of carnitine ester accumulation.
mesh_terms: D000818:Animals; D001013:Aorta, Thoracic / Q000201:enzymology / Q000378:metabolism*; D002331:Carnitine / Q000031:analogs & derivatives* / Q000494:pharmacology; D002791:Cholesterol, Dietary / Q000494:pharmacology*; D006868:Hydrolysis; D007700:Kinetics; D008297:Male; D008861:Microsomes / Q000201:enzymology*; D010172:Palmitoylcarnitine / Q000378:metabolism*; D011817:Rabbits; D002785:Sterol O-Acyltransferase / Q000378:metabolism*
chemical_list: D002791:Cholesterol, Dietary; D010172:Palmitoylcarnitine; D002785:Sterol O-Acyltransferase; D002331:Carnitine