Insulin receptors in isolated adipocytes from rats with different neonatal nutrition.

The influence of different neonatal nutrition on the properties of insulin receptor in isolated adipocytes was studied. The changes of neonatal nutrition were achieved by adjustment of the number of sucklings to 4, 8 and 14 per one litter. After weaning (at the age of 30 days) the animals were fed standard pelleted diet ad libitum. The isolated fat cells from male rats neonatally overfed (i.e. 4 per litter), underfed (i.e. 14 per litter) and control group (i.e. 8 per litter) aged 30, 60, 120 and 500 days were prepared and used for insulin binding studies. The results showed that the total number of insulin receptors is the same in small and large adipocytes from neonatally over- or underfed animals, but a negative correlation between insulin binding sites per unit of surface area and fat cell size was found. The smaller adipocytes from neonatally underfed rats apparently showed a higher binding affinity to insulin as compared to larger fat cells from neonatally overfed animals.