Figure 1.

Relaxant effects of CEPN on high K⁺-induced precontraction. (a) High K⁺ induced a steady-state contraction in a mouse tracheal ring, which was inhibited by CEPN in a concentration-dependent manner. (b) Dose-relaxation curve of CEPN based on the results of 7 different experiments shown in (a). (c) High K⁺-induced precontraction was completely blocked by nifedipine. This experiment was performed in 8 tracheal rings from 8 mice, and the result was reproducible across experiments. (d) CEPN had no effect on resting tension in 4 rings. These results indicate that the CEPN-induced relaxation might result from blockade of VDCCs.