Metabolic turnover of fatty acids, cholesterol and lipoproteins in response to atherogenic factors in experimental atherosclerosis.
In experiments on two animal species we studied the effect of age, altered motor activity and alimentary experimental atherosclerosis on a variety of variables of lipid metabolism, particularly on cholesterol and fatty acid levels and formation. Fatty acid and cholesterol cumulation in tissues, including the rat aorta, increases with age (from 2 to about 20 months of age), while their formation decreases. A decrease of motor activity seems to be at play in this phenomenon in older animals and is apparently due especially to a faster rate of decrease of lipid degradation with ageing. Enforced increase of motor activity in rats (60 or 120-day adaptation on a treadmill - 18 m/min/3 hr/day) results in a decreased tissue cumulation of lipids including cholesterol despite their increased formation. In animals of the same age but allowed a limited amount of motor activity the situation produces reverse changes in lipid levels and formation. Changes in lipid metabolism are effected also by a higher level of spontaneous activity (induced by a higher number of young in the litter) and by increased motor activity of the dams during pregnancy. Hyperkinetic animals show a uniform exogenous (alimentary) cholesterol turnover. However their alimentary cholesterol absorption and high-density lipoprotein cholesterol turnover are elevated. Two respectively 10 months following the intake of 2% of dietary cholesterol minipigs exhibit elevated cholesterolaemia, reduced endogenous cholesterol synthesis in the liver and the aorta versus a decreased endogenous fatty acid synthesis. Plasma/vascular wall cholesterol transport in hypercholesterolaemic animals is about 50% higher, while the level of cholesterol in the medium remains constant. Most experimental animals show histologic evidence of incipient atheromatous changes not earlier than 10 months following the start of experimental diet.
D000375:Aging; D000818:Animals; D001161:Arteriosclerosis / Q000378:metabolism*; D002784:Cholesterol / Q000378:metabolism*; D002791:Cholesterol, Dietary / Q000008:administration & dosage; D005227:Fatty Acids / Q000378:metabolism*; D005260:Female; D008074:Lipoproteins / Q000378:metabolism*; D008297:Male; D005082:Physical Exertion; D051381:Rats; D011919:Rats, Inbred Strains; D013552:Swine
D002791:Cholesterol, Dietary; D005227:Fatty Acids; D008074:Lipoproteins; D002784:Cholesterol