Blockade of the 32P phosphate flush of pancreatic beta cells from adult rats who received a low-protein diet during early lactation

RESUMO

In order to study the effect of nutrition on the onset of disturbances in Wistar rat pancreatic beta cells, we compared the effects of a low protein diet (8 per cent protein) and a normal protein diet (25 per cent protein) supplied to the dams (6 in each group) during the first 12 days of lactation. The parameter evaluated was the beta cells phosphate flush in response to stimulatory concentration of glucose (16.7 mM) of isolated islets of Langerhans from 60-day old pups. Using a collagenase digestion technique, islets were isolated from the pups and the 32P fractional outflow rate (FOR) of the beta cells was used as a metabolic index in both experimental groups (N = 36). We observed that although the weights of the pups of the two groups were not significantly different at 60 days of age (control = 186 +/- 18 g; undernourished during lactation = 179 +/- 19 g), the typical phosphate flush response (FOR = 2.4 +/- 0.4 per cent /min) to a stimulatory glucose concentration (16.7 mM) was abolished in the rats from undernourished mothers. Our data are consistent with the hypothesis that undernutrition may be an important cause of diabetes mellitus type II