Attempt to antagonized the stimulatory effect or ATP on insulin secretion

An attempt was made to antagonize the stimulatory effect of ATP on insulin secretion from the isolated perfused rat pancreas. The insulin secretory effect of ATP does not seem to be mediated by cholinergic or beta-adrenergic receptors since neither atropine 0.3 micro mol/1 nor propranolol 1 micro mol/1 had any antagonistic action on insulin secretion induced by ATP (16.5 micro mol/1). Theophylline (50 micro mol/1) did not antagonize the insulin secretion evoked by ATP (16.5 micro mol/1). Apamin (10 nmol/1) was also without antagonistic action. 2-2'Pyridylisatogen tosylate (5 micro mol/1) had not effect on insulin secretion induced by glucose )8.33 mmol/1) or acetylcholine (0.5 micro mol/1 and 0.1 micro mol/1) but inhibited the insulin secretory effect of ATP (16.5 micro mol/1). Thus, the antagonism of 2-2'pyridylisatogen for ATP seems selective. We conclude that a purinoceptor of the P2-type is likely to be present on the B-cell of the rat pancreas.