Interaction of insulin with small intestinal epithelial cells from developing rats.

The interaction of insulin with its specific receptors was studied in jejunoileal epithelial cells from 14-, 20-, and 60-day-old rats. Characteristics such as potency and specificity of the insulin receptor system did not vary during development. However, insulin binding decreased with age due to a diminished concentration of insulin receptors, whereas the circulating levels of the hormone followed an inverse evolution. These results support previous suggestions on the potential role of insulin on the mechanisms of differentiation and proliferation of small intestinal mucosa.