Effects of insulin on hepatic lipid synthesis in alloxan diabetic rats

In vitro hepatic synthesis of lipids starting from l-¹⁴C-acetate was studied in rats made diabetic by subcutaneous alloxan administration (175 mg/kg b.w.). A second group of diabetic rats was treated with lente insulin.

In the alloxan-treated rats, a decrease was observed in hepatic incorporation of l-¹⁴C-acetate into phospholipids, triglycerides and esterified cholesterol; there was an increased incorporation into nonesterified fatty acids (NEFA) and free cholesterol.

Insulin administration restored lipid synthesis values to normal.

On histologic examination, an intranuclear glycogenesis was observed in the hepatocytes of the alloxan-treated rats, along with severe hepatic necrosis; the latter however, only in rats sacrified on the 3rd day. Hepatic steatosis with small, medium and large droplets was present in the insulin-treated rats; signs of cellular degeneration were less evident.