The Effect of Various Fat-Enriched Diets on the Serum and Liver Lipids in Healthy and Alloxan-Diabetic Rats

Abstract

The lipid concentrations in the serum and liver and the histopathological alterations of the liver have been investigated in both healthy and alloxan-diabetic rats kept for 6 weeks on experimental diets with different fat supplements.Serum total glycerol levels were elevated only in the 10 percent lard group of the healthy animals. In the diabetic animals, however, serum total glycerol was elevated in all fat-fed groups except in those which received cholesterol alone; the highest levels were found in the 10-percent lard group. Serum cholesterol concentrations were increased in all groups on experimental diets. The elevation was greater in the diabetic animals than in the normals, the increase being most pronounced in the cholesterol and lard groups. Hepatic total glycerol concentrations were elevated in all the fat-fed healthy animals. But only in those diabetic groups which received fat and cholesterol were the concentrations elevated; they were still lower than in the corresponding healthy groups. Hepatic cholesterol levels were also increased in all the fat-fed healthy rats but only in the diabetics kept on cholesterol-supplemented diets. The hepatic cholesterol values of those groups, however, were higher than in the corresponding non-diabetics. The histopathological changes of the liver corresponded to the biochemical data. Infiltration of lipids could be demonstrated first of all in the peripheral and intermediary zones of the hepatic lobules. Although cholesterol and cholesterol crystals in the healthy animals were found in the same areas as neutral fats, the liver in the diabetic animals characteristically displayed a separated localization of cholesterol and neutral fat deposits. Mainly in the cholesterol-fed groups there was evidence of fatty cirrhosis in its beginning stage. This was even more pronounced in the diabetic rats than in the non-diabetics.