Effect of actin microfilament on potassium current in guinea pig gastric myocytes

作     者：Xiang-LanLi Hai-FengZheng Zheng-YuanJin MengYang Zai-LiuLi Wen-XieXu 

作者机构：DepartmentofPhysiologyYanbianUniversityCollegeofMedicineYanji133000JilinProvinceChina DepartmentofPhysiologyShanghaiJiaotongUniversitySchoolofMedicine1954HuashanRdShanghai200030China 

出 版 物：《World Journal of Gastroenterology》 (世界胃肠病学杂志（英文版）)

年 卷 期：2004年第10卷第22期

页      面：3303-3307页

核心收录：

学科分类：1002[医学-临床医学] 100201[医学-内科学(含：心血管病、血液病、呼吸系病、消化系病、内分泌与代谢病、肾病、风湿病、传染病)] 10[医学] 

基　　金：Supported by the National Natural Science Foundation of China No.30160028 

主　　题：影响作用 肌动蛋白微丝 钾电流 胃疾病 肌细胞 消化系统 

摘      要：AIM: To investigate the effect of actin microfilament on potassium current and hyposmotic membrane stretch-induced increase of potassium current in gastric antral circular myocytes of guinea pig. METHODS: Whole-cell patch clamp technique was used to record potassium current in isolated gastric myocyes. RESULTS: When the membrane potential was clamped at -60mV, an actin microfilament disruptor, cytochanlasin-B (Cyt-B, 20μmol/L in pipette) increased calcium-activated potassium current (IK（Ca）) and delayed rectifier potassium current (IK（V）)to 138.4±14.3% and 142.1±13.1%respectively at +60mV. In the same condition, an actin microfilament stabilizer phalloidin (20μmol/L in pipette)inhibited IK（Ca） and IK（V） to 74.2±7.1% and 75.4±9.9% respectively. At the holding potential of -60mV, hyposmotic membrane stretch increased IK（Ca） and IK（V） by 50.6±9.7% and 24.9±3.3% at +60mV respectively. In the presence of cytochalasin-B and phalloidin (20μmol/L, in the pipette)condition, hyposmotic membrane stretch also increased IK（Ca） by 44.5±7.9% and 55.7±9.8% at +60mV respectively. In the same condition, cytochalasin-B and phalloidin also increased IK（V） by 23.0±5.5% and 30.3±4.5% respectively. However, Cyt-B and phalloidin did not affect the amplitude of hyposmotic membrane stretch-induced increase of IK（Ca） and IK（V）. CONCLUSION: Actin microfilaments regulate the activities of potassium channels, but they are not involved in the process of hyposmotic membrane stretch-induced increase of potassium currents in gastric antral circular myocytes of guinea pig.