Vagovagal stimulation of pancreatic-polypeptide secretion by graded distention of the gastric fundus and antrum in man.

Previous studies have shown that pancreatic polypeptide (PP) secretion is regulated by efferent, vagal stimulation. In the present study the afferent part of a vagovagal pathway has been investigated in two different ways: (I) Graded fundic distention: in 8 patients with duodenal ulcer ballon distention with 150 ml of the fundus and the body of the stomach increased PP concentrations in plasma from 19 (17--26) to 41 (35--48) pmol/l, median and interquartile range. Distention by 300 and 600 ml did not further increase PP concentrations. After denervation of the fundus by proximal gastric vagotomy, no increase in PP levels was observed during distention with 50 and 300 ml whereas distention by 600 ml was followed by a small increase. (II) Graded antral distention: balloon distention with 50, 100 and 150 ml of the antrum increased plasma PP concentrations in 7 healthy subjects and 14 duodenal ulcer patients. Maximal PP response was achieved by distention with 100 ml, healthy subjects: from 14 (12--23) to 40 (26--44) pmol/l, and duodenal ulcer patients: from 25 (13--38) to 47 (22--63) pmol/l, median and interquartile range. It is concluded that a gastropancreatic reflex stimulating PP secretion through a long vagovagal pathway is present in man, and that this mechanism probably is involved in the initial PP response during a meal.