MODULATION OF PURINERGIC NEUROTRANSMISSION BY ECTO-ATPASE

The role of ecto-ATPase in modulating the purinergic component of neur otransmission in the guinea-pig vas deferens has been investigated usi ng ARL 67156, a recently developed inhibitor of ecto-ATPase. ARL 67156 rapidly and reversibly potentiated neurogenic contractions in a conce ntration-dependent manner ARL 67156 also potentiated contractions evok ed by exogenous ATP, but had no effect on those to the stable analogue alpha,beta-methyleneATP or on those to noradrenaline and KCl in the p resence of the P-2-purinoceptor antagonist PPADS. These results are co nsistent with an inhibitory action of ARL 67156 on ecto-ATPase and sug gest that ecto-ATPase modulates purinergic neurotransmission in the gu inea-pig vas deferens. (C) 1996 Academic Press Ltd