Effect of adenosine and phosphated derivatives on insulin release from the newborn dog pancreas

The effects of four adenine derivatives at the same concentration (16.5 micromol/l) were studied on the insulin secretion from the isolated, perfused, newborn dog pancreas. 1. Adenosine triphosphate (ATP) and adenosine diphosphate (ADP) induced an immediate and considerable insulin secretion which persisted during the 30 min administration period. When these adenine derivatives were withdrawn, the insulin secretion rapidly decreased, however it remained higher than the starting value. 2. Adenosine monophosphate (AMP) and adenosine elicited and increase of insulin secretion which was much less than that induced by ATP and ADP. This secretion did not decrease after stopping AMP and adenosine. 3. Thus, the four adenine derivatives may be divided into two groups in regard to their insulin secretory action: ATP and ADP on one hand, and AMP and adenosine on the other. The relative order of agonist potency ATP greater than or equal to ADP greater than AMP greater than or equal to adenosine is the same as that described by BURNSTOCK for P2 purinoceptors. These purinergic receptors on the B cell membrane seem to be involved in the regulation of insulin secretion.