[The effect of insulin on hyperlipoproteinemia induced by a semi-synthetic diet rich in saturated fats in a rabbit].

The influence of insulin therapy on changes in the lipoprotein profile induced by a semi-synthetic saturated-fat diet was studied in the rabbit. Hypercholesterolemia, observed after two months diet, corresponded to an increase in all lipoprotein fractions as well as an enrichment in cholesterol esters of VLDL and LDL. Treatment with insulin had only a slight effect on the increase in the lipoproteins, but completely prevented the appearance of abnormal LDL. Changes in the lipoprotein profile were markedly aggravated, without an additional increase in plasma cholesterol, when the semi-synthetic diet was continued for six months. All lipoprotein fractions showed increases in cholesterol esters and in free cholesterol at the expense of triglycerides and proteins. The animals receiving the semi-synthetic diet and treated with insulin showed decreased glucose tolerance but no additional modifications in the lipoprotein profile or in the composition of aortic tissue. Therefore, insulin initially prevents alterations in LDL, induced by the semi-synthetic diet, prevention which is not maintained in the long term.