Salivary peptide P-C modulates both insulin and glucagon release from isolated perfused rat pancreas.

The effect of salivary peptide P-C, saliva-derived peptide on glucose-induced insulin release was studied using perfused rat pancreas. Salivary peptide P-C (194 nM) remarkably potentiated glucose (8.3 and 16.7 mM)-induced insulin release, whereas the same concentration suppressed arginine (10 mM)-induced glucagon release. Both effects of salivary peptide P-C occurred in a concentration-dependent manner. These findings suggest that salivary peptide P-C may modulate both the levels of insulin and glucagon in vivo.