The development of glucose metabolism in infants of diabetic mothers.

The concentrations of plasma glucose, lactate and phosphoenolpyruvate carboxykinase (PEPCK) (EC 4.1.1.32) were studied in caesarian-delivered newborn rats of diabetic mothers (IDM) and normal mothers, at time-intervals up to 6 hr after delivery. Glucose concentrations in plasma of cord blood of IDM were significantly higher than those in normal newborn rats. The glucose concentration of normal newborn rats decreased markedly during 1 hr after delivery and thereafter increased gradually. However, the glucose concentration of IDM decreased to a minimum at 4 hr after delivery and thereafter increased. Lactate concentration in plasma of cord blood was high at delivery. Plasma lactate concentration of normal newborn rats decreased rapidly during 2 hr after delivery. However, plasma lactate concentration of IDM increased during 1 hr after delivery and thereafter decreased markedly over the next 5 hr. Hepatic soluble PEPCK activity in caesarian delivered rats was low at birth. The activity of normal infants increased after a lag of 2 hr whereas the activity of IDM increased after a lag of 4 hr. The concentrations of plasma glucose and hepatic PEPCK activity were measured as a function of time after the administration of glucose (5 g/kg body weight) to caesarian-delivered newborn rats. The glucose concentration increased to a maximum at 2 hr after administration and decreased markedly over the next 2 hr. The development of enzyme activity was delayed in administered rats. The glucose concentration and hepatic PEPCK activity were measured as a function of time after the intraperitoneal injection of insulin (250 mU/rat) into caesarian-delivered rats from diabetic pregnant rats.(ABSTRACT TRUNCATED AT 250 WORDS)