Effect of erythromycin on pancreatic polypeptide release: role of the vagal nerve

To determine whether long vagal cholinergic pathways are involved in erythromycin-induced pancreatic polypeptide release, erythromycin was administered as an intravenous bolus injection to 9 healthy volunteers (group A) and to 13 patients (group B) with impaired vagal function as a result of truncal vagotomy or accidental vagotomy after antireflux surgery. In 7 of these patients (group B1) an antrectomy was also performed, while in the other 6 patients (group B2) the antrum was not removed. Pancreatic polypeptide was measured by radioimmunoassay at 5-min intervals twice before and at 2, 5, 10, 15, 30, 45 and 60 min after a 3.5 mg/kg bolus injection of erythromycin. On another day, a standard meal was administered and plasma pancreatic polypeptide was measured at 10-min intervals for 1 h. Erythromycin injection resulted in a lower integrated pancreatic polypeptide response in the patients of group B1 (247 +/- 89 pmol/l x 15 min; p = 0.005) and group B2 (497 +/- 111 pmol/l x 15 min; p = 0.05) when compared to the healthy subjects of group A (1,136 +/- 227 pmol/l x 15 min). The pancreatic polypeptide response to erythromycin in group B1 was reduced when compared to group B2, but the difference just failed to reach statistical significance (0.05 < p < 0.10). In the first 30 min after ingestion of a meal (cephalic phase) pancreatic polypeptide release was also markedly lower in group B1 (1,461 +/- 304 pmol/l x 30 min; p < 0.005) and group B2 (1,452 +/- 215 pmol/l x 30 min; p < 0.005) when compared to group A (3,541 +/- 452 pmol/l x 30 min).(ABSTRACT TRUNCATED AT 250 WORDS)