蜘蛛毒素GsMTx-4对心脏力敏感大电导钾通道的抑制作用  

Inhibitory effect of spider toxin GsMTx-4 on stretch-activated large conductance calcium-activited potassium channel in the heart

作　　者：唐晓冬[1] 李辉[1] 杜项荣 张飞飞[1] 冯验军 卜薪涵 张赭[1] 唐琼瑶[1] TANG Xiaodong LI Hui DU Xiangrong et al(Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou 221004, CHINA)

机构地区：[1]徐州医科大学江苏省麻醉学重点实验室,江苏省221004

出　　处：《江苏医药》2017年第1期4-7,F0002,共5页Jiangsu Medical Journal

基　　金：国家自然科学基金(84150064);江苏省高等学校大学生实践创新训练计划(201510313006;201510313006Z)

摘　　要：目的探讨蜘蛛毒素GsMTx-4对在中国仓鼠卵巢癌(CHO)细胞中表达的心脏力敏感大电导钾通道(SAKca通道)电流的影响。方法在CHO细胞中瞬时转染以表达SAKca通道蛋白,采用电极内倒灌流法和内面向外式膜片钳技术研究SAKca通道电流特性及GsMTx-4对SAKca通道电流的影响。结果当膜电位在-140~100mV范围时,SAKca通道电导值为(276.6±4.5)pS。与0mmHg压力相比,-30mmHg的压力使SAKca通道开放频率(Po)-膜电位曲线向左平移了(23.3±3.1)mV。通过倒灌流法在电极内加入100nmol/L的GsMTx-4,SAKca通道Po在10min内降低了75%左右。结论 GsMTx-4对SAKca通道电流有抑制作用。Objective To investigate the effect of the spider toxin GsMTx-4 on cardiac stretchactivated large conductance calcium-activited potassium channel（SAKca channel） current expressed in Chinese hamster ovary（CHO） cells. Methods SAKca channel proteins were expressed in CHO cells by transient transfection. The properties of SAKca channel current and the effect of GsMTx-4 on SAKca channel current were tested using the back-fill method and inside-out patch clamp technique. Results The conductance of SAKca channel was （276.6±4. 5） pS when the membrane potential was in the range of -140 mV to 100 mV. Compared with the pressure of 0 mmHg, the pressure of -30 mmHg made a left shift of （23.3±3.1） mV in the open probability-membrane potential curve. After GsMTx-4 100 nmol/L was added into the pipette using the back-fill method, the open probability of SAKca channel reduced nearly by 75% in 10 minutes. Conclusion GsMTx-4 inhibits the SAKca channel current expressed in CHO cells.

关 键 词：大电导钾通道 力敏感通道 蜘蛛毒素GsMTx-4 膜片钳 

分 类 号：R913[医药卫生—药学]