Effect of C-peptide on insulin and glucagon release by isolated perfused rat pancreas

Administration of rat C-peptide (0.1 mumol/l) to isolated rat pancrease failed to inhibit insulin release induced by a high concentration of D-glucose (11.1 mmol/l) but prevented the progressive increase in insulin output otherwise observed during prolonged perfusion in the presence of 3.3 mmol/l glucose and 5.0 mmol/l L-arginine. In these experiments, C-peptide failed to affect glucagon output. The findings suggest that in suitable conditions C-peptide can inhibit insulin release.