Effects of neonatal nutrition on glucagon binding and glucagon stimulated cAMP production in isolated rat hepatocytes.

The effect of neonatal nutrition on glucagon receptors and cAMP production was studied in isolated rat hepatocytes. Nutritional differences were obtained by changing the number of suckling pups per litter to 4 (RV4; neonatally overfed group), 8 (RV8; controls), and 14 (RV14; neonatally underfed group). After weaning the animals had free access to standard diet. Three age groups (60, 120 and 580 days) were investigated. Specific 125I-glucagon binding to isolated hepatocytes was elevated in RV14 animals of all age groups. Increased number of high- and low affinity glucagon receptors was observed in hepatocytes of RV14 rats of all age groups. The differences in neonatal nutrition did not influence glucagon binding affinity constants or the basal and maximum stimulated cAMP production. However, an increase in sensitivity of cAMP production to glucagon stimulation was found in hepatocytes of neonatally underfed rats of all age groups. Neonatal undernutrition in rats was associated with both increased hepatocyte glucagon receptors and a higher sensitivity of cAMP production to hormone stimulation.