[Glucose-assimilation and dynamics of insulin secretion. Measurements after intra-abdominal operations (author's transl)].

Insulin concentrations in peripheral venous blood and portal venous blood were measured in 18 patients after intraabdominal operations during 20 standardised glucose-infusion-tests (GIT). The conclusion is as follows: 1. In spite of similar preoperative situations and operative traumatisation the islets reactivity to a constant hyperglycemia and the glucose assimilation is individually ver different. 2. Measurements of insulin concentrations in the portal venous blood in man show a significant correlation between the profile of the insulin concentration curve and the k-value; the measurement of the insulin concentrations in peripheral venous blood fails to demonstrate a significant difference. 3. In patients with a pathologic glucose assimilation it is not the insulin secretion that is delayed but the insulin regression (disappearance rate) in portal venous blood. 4. In patients with a normal glucose assimilation the insulin concentrations curve in portal venous blood shows an oscillating course during the first 30 min. These oscillations registered for the first time in humans indicate an insulin-induced feedback mechanism of insulin secretion.