[Ecto-ATPases and receptors for ATP].

Although enzymes which metabolize extracellular ATP (ecto-ATPases) have been described long ago, it has only recently become clear that such enzymes play an especially important role in cells possessing ATP receptors (P2-purinoceptors). In this review the authors characterize common features of ecto-ATPases, underlining the differences between these enzymes and other ATP-metabolizing enzymes. The authors also review their own recent studies dealing with the effects of various compounds on enzyme activity and on P2-purinoceptor-mediating responses. Since most known P2-purinoceptor antagonists inhibit ecto-ATPase activity, it is important to search for selective P2-purinoceptor antagonists as well as ecto-ATPase inhibitors.