Liu Xian-sheng, Xu Yong-jian, Zhang Zhen-xiang, Ni Wang
Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
Yao Xue Xue Bao. 2003 May;38(5):333-6.
To investigate the effects of blockers of the three kinds of potassium channels: voltage-dependent K+ channel(KV), calcium-activated K+ channel(KCa) and ATP-sensitive K+ channel(KATP), on the proliferation of rat bronchial smooth muscle cells (BSMCs).
The effects of three kinds of potassium channel blockers on the proliferation of BSMCs were detected by MTT method, immunocytochemistry staining and flow-cytometry. Their effects on the dynamic changes of Ca2+ concentration in BSMCs were investigated by the fluorophotometry of Fura-2/AM.
The KV blocker 4-aminopyridine (4-AP) was shown to significantly increase the expression of proliferating cell nucleus antigen in cultured rat BSMCs (P < 0.01), but the KCa blocker tetraethylammonium (TEA) and KATP blocker glibenclamide(Glib) did not show such effect (P > 0.05). 4-AP was found to significantly increase the optical density value of the cultured BSMCs (P < 0.01) by MTT method and the numbers of S + G2M BSMCs(P < 0.05) by flow-cytometry. TEA and Glib did not show such effects. 4-AP significantly increased the Ca2+ concentration in cultured BSMCs(P < 0.01). TEA and Glib did not show such effects.
This result suggests that inhibition of KV activity can increase intracellular Ca2+ and proliferation of rat BSMCs, but inhibition of KCa and KATP showed no effect.
研究三种钾通道阻滞剂，即电压依赖性钾通道（KV）、钙激活钾通道（KCa）和ATP敏感性钾通道（KATP），对大鼠支气管平滑肌细胞（BSMCs）增殖的影响。
采用MTT法、免疫细胞化学染色和流式细胞术检测三种钾通道阻滞剂对BSMCs增殖的影响。采用Fura-2/AM荧光光度法研究它们对BSMCs中Ca2+浓度动态变化的影响。
电压依赖性钾通道阻滞剂4-氨基吡啶（4-AP）可显著增加培养的大鼠BSMCs中增殖细胞核抗原的表达（P<0.01），但钙激活钾通道阻滞剂四乙铵（TEA）和ATP敏感性钾通道阻滞剂格列本脲（Glib）未显示出这种作用（P>0.05）。MTT法检测发现4-AP可显著增加培养的BSMCs的光密度值（P<0.01），流式细胞术检测发现其可增加S+G2M期BSMCs的数量（P<0.05）。TEA和Glib未显示出这种作用。4-AP可显著增加培养的BSMCs中的Ca2+浓度（P<0.01）。TEA和Glib未显示出这种作用。
该结果表明，抑制电压依赖性钾通道活性可增加细胞内Ca2+浓度并促进大鼠BSMCs增殖，但抑制钙激活钾通道和ATP敏感性钾通道则无此作用。
