Glucagon, insulin, and growth hormone response to exchange transfusion in premature and term infants.

were performed on premature or term infants using blood preserved with acid citrate and glucose. The plasma concentrations of glucose, free fatty acids, insulin, glucagon, and growth hormone were measured in the donor blood and in blood from the infant at different times during the transfusion. The total amounts of metabolite and hormone infused and removed from the infant were calculated. The exchange transfusion caused a larger rise in plasma glucose of premature infants than of term infants, due in part to a higher plasma glucose in the donor blood used for premature infants. Despite the higher plasma glucose levels, the premature infants secreted less insulin in response to the glucose challenge, as judged by the rise in plasma insulin and the insulin balance. The transfusions were associated with increased growth hormone secretion in both groups. Premature infants secreted more growth hormone