Impaired pancreatic innervation after selective gastric vagotomy. Reduction of the pancreatic polypeptide response to food and insulin hypoglycemia.

The secretion of pancreatic polypeptide (PP) was studied in 38 duodenal ulcer patients before, 4 months after, and, in 25 patients, again 18 months after either selective gastric vagotomy or parietal cell vagotomy. Selective gastric vagotomy on average reduced the PP response to food measured 4 months after operation to 20% of the preoperative value. The prolonged PP response (30-120 min) increased to 50% from the 4th to the 18th postoperative month (p less than 0.005). Parietal cell vagotomy did not significantly change the PP response to food, although in a few patients (3/15) the response was reduced to below one third of the preoperative value. The PP response to insulin hypoglycemia was measured after operation in 16 patients; those who had a reduced PP response to food demonstrated a response to hypoglycemia which was reduced to the same extent. It is concluded that PP secretion is generally unaffected by parietal cell vagotomy but is impaired after selective gastric vagotomy and that the prolonged PP response to food is partially regenerated after vagotomy. It is suggested that selective gastric vagotomy interferes with the vagal innervation of the PP-rich head of the pancreas.