Effect of adenosine versus adenine nucleotides on evoked potentials in a rat hippocampal slice preparation.

A marked depression of evoked CA1 potentials was observed with the nucleotide analogues a,b-methylene ADP (AOPCP) and adenylimido-diphosphate (AIP) and with 2'-adenosine monophosphate (2'-AMP). While the depression elicited by 5'-nucleotides was completely antagonized by the action of adenosine deaminase, AOPCP and 2'-AMP were only partially antagonized. The findings indicate that nucleotides on their own are capable of modulating synaptic transmission but that the physiologically more prevalent 5'-AMP is mediating its effect via adenosine. By producing this membrane permeable compound and allowing its re-uptake, the 5'-nucleotidase may determine the time course of purinergic action.