Salivary Secretion of Rat Haptocorrin and Amylase Is Stimulated by Vasoactive Intestinal Polypeptide

Rat salivary glands secrete the cobalamin-binding protein haptocorrin and the enzyme amylase. We report the secretion to be stimulated in a dose-dependent manner by vasoactive intestinal polypeptide (VIP). VIP especially enhances the secretion of amylase. The concentration of amylase increases in saliva and in serum while the concentration of haptocorrin increases only in saliva. Serum contains a cobalamin-binding protein that differs from the binding protein in saliva. The serum cobalamin-binding protein is classified as transcobalamin.