Programming into adulthood of islet adaptations induced by early nutritional intervention in the rat

To investigate the influence of a high carbohydrate (HC) intake during the suckling period on pancreatic function in adult life, neonatal rats were ar tificially reared on a HC milk formula during the preweaning period and the n weaned onto lab chow. In the adult HC rat, hyperinsulinemia is sustained by a variety of biochemical and molecular adaptations induced in the HC isl ets during the suckling period. The adult HC islets showed a distinct left shift in the glucose-stimulated insulin-secretory pattern. HC islets were a lso able to secrete moderate levels of insulin in the absence of glucose an d in the presence of Ca2+ channel inhibitors. In addition, the mRNA levels of preproinsulin, somatostatin transcription factor-1, upstream stimulatory factor-1, stress-activated protein kinase-2, phosphatidylinositol kinase, and GLUT-2 genes were significantly increased in HC islets. These results s how that consumption of a HC formula during the suckling period programs pa ncreatic islet function in adult rats, resulting in the maintenance of hype rinsulinemia in the postweaning period and eventually leading to the develo pment of obesity in adult life.