Table 1

Antagonist activity at a novel P1 receptor

AntagonistIC50 valuepIC50 valueSlope (nH)Comments
μM −log IC50
α,β-meATP0.19  ± 0.036.72  ± 0.070.83  ± 0.15Reversible
8-SPT0.21  ± 0.016.68  ± 0.021.71  ± 0.13Reversible
Theophylline4.8  ± 3.35.32  ± 0.370.57  ± 0.06Reversible
PIT26.1  ± 4.54.58  ± 0.071.47  ± 0.09Irreversible
Suramin>100Inactive

Shown are the activity indices, slope of inhibition curves and reversibility of five compounds tested as antagonists of the adenosine/ATP receptor in follicular Xenopus oocytes. Data represent mean ± S.E.M. for four experiments per compound.