[Lipid and lipoprotein metabolism in rats on a normal and atherogenic diet]

The authors carried out experimental studies on four groups of experimental animals at various age and three groups of animals, fed with atherogenic diet according to O'Neal for a period of 4, 11 and 12 months. It was established that the level of serum lipids and lipoproteins underwent substantial changes in the period of sexual maturation. There was no difference between the adult and old animals. The sligh-test changes was found in cholesterol, but the level of triglycerides, esterified fatty acids and total lipids in old animals was even lower than of the adult animals. There was a tendency to an increase of all lipid fractions in the liver of old animals. Cholesterol and beta-lipoproteids were elevated in the aorta of the old animals. Feeding with atherogenic diet for 4 months induced an accumulation of liver lipids without hyperlipidemia and hyperlipoproteinemia, but continuous feeding with atherogenic diet induced also manifested hyperlipidemia and hyperlipoproteinemia besides an increase in liver lipids. Morphologically in these animals there was an infiltration of peripheral parts of liver lobules as well deposition of sudonophil substances in subendothelial space of the aortic wall. Stopping of ah tero genic diet 20 days before killing of the experimental animals was enough to reduce significantly the level of liver lipids, but not that in serum and aorta. The most lasting changes underwent triglycerides respectively esterified fatty acids. The studies show that the ah terogenic diet cause characteristic changes in lipid and lipoproteid metabolism, which, however, are different from the changes, which occur with aging of the organism.