Dual effects of tetrandrine on calcium-activated potassium channels in pulmonary artery smooth muscle cells
Wang, Z.F.; Kai, L.; Xiao, X.R.
Zhongguo Yao Li Xue Bao 20(3): 253-256
1999
ISSN/ISBN: 0253-9756 PMID: 10452102 Document Number: 501216
AIM: To study the effects of tetrandrine (Tet) on calcium-activated potassium channels. METHODS: Inside-out configuration of patchclamp single channel recording techniques. RESULTS: Tet 7.5 and 15 mumolcntdotL-1 increased the open probability from control value 0.251 +- 0.012 to 0.340 +- 0.013 and 0.415 +- 0.011, respectively (P < 0.01), decreased the close time from (61 +- 15) ms to (33 +- 10) and (28 +- 11) ms, respectively (P < 0.01). But Tet 30 mumolcntdotL-1 decreased the open probability and open time to (0.114 +- 0.008) and (1.47 +- 0.09) ms, respectively (P < 0.01 vs control (0.251 +- 0.012) and (20 +- 8) ms). CONCLUSION: Tet has concentration-dependent dual effects on KCa channels in isolated rat pulmonary smooth muscle cells.