Effects of Insulin on Metabolism of Perfused Livers of Rats Made Acutely Diabetic by Anti-insulin Serum Injection

Livers were taken from fed rats injected ninety to 120 minutes earlier with guinea pig anti-insulin serum and were perfused for four hours with and without addition of insulin to the medium. Glucose-l-C-14, glucose-6-C-14, and acetate-H-3 were added as tracers. The major changes from normal were (1) decreased initial glycogen content, (2) decreased fatty acid synthesis, and (3) decreases in oxidation to CO₂ of both glucose-l-C-14 and glucose-6-C-14. Fatty acid synthesis was correlated with initial glycogen content, which varied widely even though the degree of hyperglycemia of the donor animal was quite consistent. Insulin added to the perfusate restored normal rates of glucose oxidation and stimulated fatty acid synthesis, although normal lipogenesis was not achieved. The data are consistent with mediation of the antiserum effects on the liver by plasma elevation of either unesterified fatty acid or glucagon.