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.