EFFECT OF ANTRECTOMY AND TRUNCAL VAGOTOMY ON ERYTHROMYCIN INDUCED PANCREATIC-POLYPEPTIDE SECRETION

Erythromycin, a motilin agonist, enhances gastrointestinal motility bu t also stimulates endogenous pancreatic polypeptide (PP) secretion. We investigated whether the effect of erythromycin on PP release is depe ndent on (1) prokinetic activity of erythromycin generated from the an trum and (2) the long vagus nerve since erythromycin acts via choliner gic neurons. Erythromycin induced PP secretion was determined in 14 pa tients with antrectomy (6 patients with Billroth I type anastomosis, 8 patients with Billroth II type anastomosis), in 6 patients with trunc al vagotomy and pyloroplasty but without gastric resection and in 8 he althy controls. Plasma PP levels in response to erythromycin (3 mg/kg i.v.) were determined at regular intervals for 180 min. Erythromycin i nduced a significant increase in plasma PP in the control subjects fro m 22 +/- 4 pmol/l (basal) to 49 +/- 4 pmol/l at 10 min. In the patient s with truncal vagotomy plasma PP secretion after erythromycin was sig nificantly (P < 0.05) increased (peak increment vs. basal: 98 +/- 10 p mol/l vs. 27 +/- 2 pmol/l) and prolonged compared to controls. In the patients with antrectomy no significant increases in plasma PP over ba sal were observed after erythromycin infusion. It is concluded that er ythromycin stimulates PP secretion in healthy controls. The PP respons e to erythromycin is exaggerated after truncal vagotomy but absent aft er antrectomy indicating that the antrum is essential for erythromycin induced PP secretion.