Secretin induces precocious cessation of intestinal macromolecular transmission and maltase development in the suckling rat.

The effect of endogenous and exogenous secretin on the intestinal closure of macromolecular transmission and maltase development were investigated in suckling rats. The increase in secretin-like immunoreactivity with orogastric infusion of HCl solution in 14 day-old pups was confirmed. By the repeated oral administration of HCl, pancreatic hyperplasia, suppression of intestinal bovine IgG transmission, and precocious induction of maltase activity were occurred. By repeated subcutaneous injection of secretin, dose-dependent suppression of intestinal bovine IgG absorption and increase in maltase activity were observed. The suppression of IgG absorption with secretin treatment was also observed in adrenalectomized pups. These results suggest that secretin affects the maturation of gastrointestinal function in suckling rats.