Metabolic and hormonal effects of glucagon infusion in erythroblastotic infants.

Abstract

, R. (1973). Archives ofDisease in Childhood, 48, 885. Metabolic and hormonal effects of glucagon infusion in erythroblastotic infants. 10 or 50 ,g glucagon was added to the bottle of donor blood, preserved with acid citrate and dextrose, used for exchange transfusion of erythroblastotic infants. The effects of the glucagon infusion on plasma glucose, insulin, growth hormone (GH), and glucagon were measured during the transfusion and for 60 minutes thereafter, and were compared with transfusions in which no addition was made to the donor blood. Both doses of glucagon produced similar effects: higher mean plasma glucose and insulin levels during the transfusion, but no significant change in plasma growth hormone levels. Transfusion with glucagonenriched blood had no effect on the net balance of glucose or growth hormone, but caused a negative insulin balance twice as big as that occurring in the control group.At the end of the control transfusions the mean plasma glucagon was 248 pg/ml and this did not change significantly in the next 60 minutes. When 10 or 50 Xug glucagon was added to the donor blood the end-transfusion mean plasma glucagon concentrations were 1302 and 3975 pg/ml, respectively. Glucagon disappeared rapidly from plasma for 5 to 10 minutes and then more slowly at the rate of 0 * 5 to 1 0 % per minute for the next 50 minutes. The range of glucose disappearance rates in the 60 minutes after transfusion (0 -40-2 13 %/min) was similar in all three groups, but the infants receiving glucagon-enriched blood had higher blood glucose levels for a given glucose disappearance rate. In each group there was a highly significant negative correlation between the 60-minute plasma glucose level and the glucose disappearance rate.

Thyroid function during exchange transfusion.

“…Although glucagon in pharmacological doses stimulates thyroid metabolism in vitro (Burke, 1970), it had no significant effect on plasma T3, T4, or TSH levels in the present situation despite raised plasma glucagon levels at the end of transfusion (Milner et al, 1973). This suggests that the human neonatal thyroid gland and thyrotroph of the pituitary are insensitive to glucagon.…”

“…Exchange transfusions were performed via the umbilical vein using blood preserved with acid-citrate and dextrose (ACD) and in some transfusions 10 or 50 jLg glucagon were added to the bottle of donor blood immediately before transfusion (Milner et al, 1972;Milner, Chouksey, and Assan, 1973). The addition of glucagon raised the plasma glucagon concentration of the donor blood to pharmacological levels and resulted in a high plasma glucagon concentration in the infants at the end of transfusion.…”

Metabolic and hormonal changes during and after exchange transfusion with heparinized or ACD blood

“…Earlier work has shown a close linear correlation between glucose disappearance and the 60-minute post-transfusion plasma glucose level (Milner, Chouksey, and Assan, 1973), suggesting that the latter might be a prognostic guide to the infants likely to become hypoglycaemic. Neither the present results nor those from transfusions performed via the umbilical artery (Cser and Milner, 1975) confirm this idea, but indicate rather that glucose homoeostasis in the second and third hours after transfusion is not closely related to the way in which the glucose load is handled in the first hour.…”

Parathyroid hormone secretion during exchange transfusion.

“…The addition of 50 jig glucagon to ACD blood results in high plasma glucagon in the infant by the end of transfusion with effects on glucose mobilization and insulin secretion (Milner, Chouksey, and Assan, 1973). Glucagon has been reported to stimulate calcitonin release from perfused thyroid glands (Care, Bates, and Gitelman, 1970) and indirect evidence suggests that chronic hyperglucagonaemia may lead to parathyroid hyperplasia (Paloyan, 1967).…”