At the neuromuscular junction, P-2-purinoceptors mediate the actions o
f the co-transmitter ATP and P-1-purinoceptors, those of its degradati
on product adenosine. The classification of the subtypes of P-1- and P
-2-purinoceptors and their signal transduction routes is presented. Pu
rinoceptor mediated effects on the prejunctional release of acetylchol
ine and the postjunctional desensitization and expression of nicotinic
receptors are discussed in depth. An additional section on the revers
al action of the P-2-purinoceptor antagonist suramin on neuromuscular
block underscores the importance of testing purinoceptor-targeted drug
s once they will be marketed, to avoid adverse effects in patients. (C
) 1997 Elsevier Science Inc.