Figure 7.

Effects of thrombin and trypsin on smooth muscle cells (SMCs)

A and B, representative traces using K⁺-rich pipette solutions showing enhancement of noisy inward currents by thrombin (A) and trypsin (B). These responses were of relatively low current density in SMC. Note also that thrombin and trypsin failed to elicit any outward current at −50 mV with K⁺-rich dialysis of cells. C, summarized data showing increase in average current density in cells after exposure 1 min and 2 min to thrombin (open bars; n = 6) and trypsin (filled bars; n = 5). *P < 0.05 compared with control. D and E show similar responses using Cs⁺-rich pipette solutions at −50 mV. These experiments demonstrate that the small responses of SMCs are not due to contamination by simultaneous generation of opposing outward currents in these cells. F, summarized data showing increase in average current density in cells after exposure to thrombin (open bars; n = 6) and trypsin (filled bars; n = 5) for 1 min and 2 min. *P < 0.05 compared with control.