钾离子通道在EGF引起细胞增殖中的作用

目的 :研究表皮生长因子 (EGF)对大鼠成骨肉瘤细胞钾离子通道活动的影响 ,探讨这种钾通道活动与细胞增殖的关系。方法 :采用膜片钳技术 ,在细胞贴附方式下用内面向外的方法记录。在含有EGF(10ng/ml)的无血清培养液中培养 2 4h后记录钾通道 ,同时用3 H -TdR掺入法及流式细胞仪测定DNA合成的变化并进行细胞周期分析。结果 :含有EGF的培养液培养细胞的钾通道电流较对照实验有明显增加 ,通道开放概率也增加。同时 ,EGF加入使细胞的3 H -TdR掺入率增加 6 4 91% ;进入S期细胞增加 35 %。在EGF作用的不同时期加入钾通道阻断剂 ,可以不同程度的抑制DNA合成 ,并且阻断剂加入时间越早 ,对DNA合成的抑制越强。结论 :钾通道在细胞进入S期或在S期的活动中起重要作用。阻断钾通道可以较明显地抑制DNA合成 ,揭示出钾通道的活动与DNA合成和细胞增殖有密切关系。

Role of K + channel in the effect of EGF on cell proliferation

Objective: To study the effect of EGF on K + channel activity in rat osteoblast-like cells line and the relationship of K + channel and cell proliferationMethods: Using Cell-attached and inside-out configurations, an inward-rectifying current was recorded After the cells were cultured in the nutrient fluid with ECF and without serum for 24 hours, K + channel was recorded At the meantime the DNA synthesis was determined and cell cycle analysesd with the methods of the 3 H-TdR incorporation and flow cytometryResults: The K + channel currents of the cells in the culture medium with EGF increased, compared with the control group EGF could also increase the open probabity of the channels And EGF was found to increase 3 H-TdR incorporation by 6491% at the physiological concentrations Cell cycle showed that 10ng/ml EGF could increase cell in S phase by 35% Addition of K + channel blocker TEA at the various times after addition of EGF, DNA synthesis could be inhibited to some degree. The earlier the addition of TEA, the stronger the blocking Conclusion: An inward rectified K + channel was identified in rat osteoblas-like cell line Maybe it plays an important role in cell proliferation when cells are in the S phase or in the action of the S phase K + channel blocker TEA could block K + channel and also diminish DNA synthesisIt indicates that the activity of K + channel has the close relationship with DNA synthesis and cell proliferation.