Immediate effect of vagotomy on pancreatic insulin secretion.

The effect of vagotomy and gastric resection on insulin secretion was examined by the glucagon stimulated C-peptide test in gastrectomy patients (n = 11) without truncal vagotomy and in total gastrectomy patients (n = 10) with truncal vagotomy. The test was performed twice in each patient: 10 minutes after the midline incision was made and then 60 to 90 minutes later when gastric resection or total gastrectomy was completed, during the reconstructive phase of the operation. Gastric resection without truncal vagotomy was followed by a higher increase (48%) in serum C-peptide concentration caused by glucagon stimulation than total gastrectomy with truncal vagotomy (13%). There was a significant (p less than 0.05) increase in the glucagon stimulated glucose-related C-peptide concentration in patients without truncal vagotomy, whereas truncal vagotomy inhibited this increase. These results suggest that truncal vagotomy will produce a reduction in stimulated insulin secretion in humans.