Fig. 3. (A ) Typical recording of intracellular free Ca2+concentration ([Ca2+]i) increase induced by thrombin (0.02 U/ml) and (+)-9,11-epithia-11,12-methano-thromboxane A2(STA2; 0.5 μm). Ketamine (250 μm, 500 μm, and 1 mm) decreased the first peak of [Ca2+]iincrease. (B ) Effect of ketamine on increase of [Ca2+]iinduced by thrombin (0.02 U/ml) and STA2(0.5 μm). Vertical line indicates the [Ca2+]iincrease at the first peak from baseline. Ketamine suppressed [Ca2+]iincrease in a dose-dependent manner (n = 4 each). Data are expressed as mean ± SD. *P < 0.01 significantly different from that with zero-control at indicated concentrations of ketamine (described in Materials and Methods).