[Potentiating synergism between alpha, beta-methylene ADP and acetylcholine on the secretion of insulin from the isolated pancreas of the newborn dog]

Abstract

A possible interaction between alpha,beta-methylene ADP, a stable analogue of ADP, and acetylcholine, was studied on insulin secretion from isolated new-born dog pancreas, perfused in the presence of a non stimulating glucose concentration (4.2 mM). alpha,beta-methylene ADP alone (16.5 microM) and acetylcholine alone (0.5 microM) induced a comparable increment of insulin secretion. When the two substances were simultaneously infused, the increment of secretion was significantly higher than the sum of the increments induced by alpha,beta-methylene ADP and acetylcholine infused separately (p less than 0.005). Our results show a potentiating synergism between alpha,beta-methylene ADP and acetylcholine, on insulin secretion, alpha,beta-methylene ADP acting via a P2 purinoceptor and acetylcholine via a muscarinic receptor. Similar results were previously obtained on the rat pancreas.