INSULIN-MEDIATED AND GLUCOSE-MEDIATED GLUCOSE-UPTAKE FOLLOWING HEMIPANCREATECTOMY IN HEALTHY-HUMAN DONORS

Healthy humans undergoing hemipancreatectomy for the purpose of donation to a family member with IDDM have previously been demonstrated to maintain serum glucose values equal to matched control subjects during short-term glucose infusion despite significant decrements in glucose- and arginine-induced insulin secretion. In order to determine whether humans compensate for hemipancreatectomy by increasing insulin- or glucose-mediated glucose uptake, we measured glucose turnover and insulin sensitivity by three protocols. Insulin-mediated glucose uptake was measured during sequential infusions of insulin at rates of 0.25, 1.0, and 10.0 mU.kg(-1).min(-1) in 12 donor subjects and 12 matched control subjects maintained at euglycaemia. Both groups displayed similar increases in rates of glucose disappearance and similar decreases in rates of hepatic glucose production. Glucose-mediated uptake was calculated as the difference between the rates of glucose disappearance measured during a hyperglycaemic clamp and a euglycaemic clamp performed at identical rates of insulin infusion and was also found to be similar in both donor subjects and control subjects. Both groups also had indistinguishable measures of insulin sensitivity and glucose effectiveness as determined by the minimal model technique. Therefore, donor subjects appear to compensate for diminished insulin secretion following hemipancreatectomy by an unidentified mechanism since neither insulin- nor glucose-mediated glucose uptake are increased.