In vitro study of liver slices lipid 1-14C-acetate incorporation in hyperlipoproteinemic subjects

The aim of the present study is to determine the "in vitro" rate of 1-14C-acetate incorporation into lipids in human liver slices from patients with various types of hyperlipoproteinemia. Hepatic tissue from type IIa hyperlipemic patients incorporated labelled acetate into free cholesterol at a higher rate than normolipidemic patients. In type IIb patients the incorporation was increased into hepatic free cholesterol, triglycerides and FFA. The liver of pre-beta hyperlipoproteinemic subjects incorporated 1-14C-acetate into triglycerides to a greater extent than hepatic tissue from controls. Triglyceride synthesis was highly elevated in type IV hyperlipoproteinemic patients with diabetes. In all cases, there was no significant correlation between increased hepatic triglyceride synthesis (dpm/mg of extracted lipids) and insulin response (microunits/ml) to oral glucose ingestion (75 g). The present data indicates that in the presence of disturbances in lipid and carbohydrate metabolism one observes an alteration of lipid synthesis in the liver. The in vitro incorporation of 1-14C-acetate into hepatic cholesterol and/or triglyceride in patients with primary hyperlipoproteinemia is increased. Thus the elevated serum cholesterol and triglyceride levels of these patients could be explained on the basis of an increased lipoprotein synthesis in the liver.