caffeine ( 100 microm ) , theophylline ( 100 microm ) and 3-isobutyl-1-methylxanthine ( 1-10 microm ) did not significantly affect the atp-induced depolarization but did reversibly depress the atp-induced hyperpolarization .
C0039771
theophylline
C0000096
3-isobutyl-1-methylxanthine