P2-receptors (P2-R), which recognise extracellular ATP, represent significa
nt targets for novel drug development regarding different pathophysiologica
l conditions. In recent years, approximately fifteen ATP receptor subtypes
have been cloned; seven of which belong to the P2X-R family (ligand-gated-i
on-channel receptors). The remaining subtypes belong to the P2Y-R family (G
-protein coupled receptors). These receptors have been classified based on
their putative molecular structure, function, and the action of a subtype s
elective drug on the cloned receptor. A limited number of reports describe
the identification of potent and selective P2X/P2Y agonists, thus extending
the restricted arsenal of P2-R agonists consisting primarily of commercial
compounds. Several new and subtype selective antagonists have been recentl
y identified which open a new avenue of P2X or P2Y subtype selective antago
nists for receptor studies. Current applications of P2-R agonists and antag
onists include their use as insulin secretagogues, inhibitors of ADP-induce
d platelet aggregation, agents for hydration of lung mucous in cystic fibro
sis (CF) patients, modulators of cardiac muscle contractility, and antineop
lastic agents. This paper reviews selected P2-R related publications and pa
tents issued between 1995 and 1998 for newly cloned P2-R, drug candidates,
and the potential therapeutic applications of the drugs.