Figure 5.

Effects of apamin on thrombin and trypsin-activated outward currents in PDGFRα⁺ cells

A and B, apamin (300 nm; added 1 min after addition of thrombin or trypsin) blocked the outward currents induced by thrombin (50 U ml^-1; A, and trypsin (1 μm; B, The holding potential in these experiments was −50 mV. C, summarized data showing the average current densities evoked by thrombin (open bars; n = 5) or trypsin (filled bars; n = 5) 2 min after the responses were initiated in cells without apamin present (these time controls were tabulated from the experiments depicted in Fig.4). In different cells, the outward currents activated by thrombin (n = 5) or trypsin (n = 5) were blocked by apamin. The ‘+Apamin bars’ show the current density 2 min after addition of thrombin or trypsin and 1 min after addition of apamin. **P < 0.01, ***P < 0.001.