Effect of Site of Administration of Insulin on Blood Glucose and Fatty Acid Concentrations

Abstract

Glucagon-free insulin, in doses of 6.0 to 12.5 m[mu]/kg of body weight, was injected into either the portal or a peripheral vein in eight unanesthetized dogs. Endoportally administered insulin was followed by a fall in systemic venous nonesterified fatty acid concentration which was significantly greater than that produced when insulin was given peripherally. On the other hand, systemically administered insulin had a greater effect on blood glucose than did the endoportally injected hormone. These results are in accord with the hypothesis that insulin secreted into the portai vein induces the liver to increase its rate of uptake of nonesterified fatty acids but has little or no effect on glucose release by the liver.