because of the known association of atp with norepinephrine in synaptic vesicles of adrenergic nerves and in view of the present evidence of a postjunctional action of atp as well as the release of tritium from 3h-adenosine-treated vasa deferentia , it seems possible that in this tissue atp , in addition to its other functions , may serve as a co-transmitter with norepinephrine .
C0001443
adenosine
C0001480
atp