Dietary alterations in polyunsaturated fatty acids in guinea-pig brain, liver and muscle

Abstract

11Ptions of cholesterol caused very marked changes in the rate of hydrolysis of soybean oil. At low concentrations of cholesterol (5%) an optimum activity occurred in the presence of 20% phospholipid. With 15% cholesterol the optimum concentration of phospholipid was 30%, and at 30% cholesterol the optimum concentration of phospholipid was 50%. The relative activity at these optimum phospholipid concentrations was 65, 100 and 70% respectively.These results show that the lipid composition of the substrate emulsion has a very marked effect on the activity of lipoprotein lipase. It is also known that surface-active agents used in the preparation of emulsions influence the activity (Fielding, 1970a; Doizaki & Zieve, 1968), but it is not yet known whether changes in plasma-lipid composition affect the tissue uptake of circulating triglyceride. The results of these experiments in vitro would suggest that the cholesterol concentration and the relative composition of the plasma lipids could be of importance in the activity of lipoprotein lipase in vtvo.