Acta Physiologica Sinica, April 25, 2003, 55(2): 177-182
Received 2002-07-16 Accepted 2002-10-23
This project was supported by the National Natural Science Foundation of China (No. 39860031).
Corresponding author. Tel: +86-433-2660586; Fax: +86-433-2659795; E-mail: wenxiexu@ybu.edu.cn
Research Paper
Role of actin
microfilament in hypoosmotic membrane stretch-induced increase in muscarinic current of guinea-pig gastric myocytes
WANG Zuo-Yu1,YU Yong-Chun1, CUI Yi-Feng1, LI Lin1, GUO Hui-Shu1, LI Zai-Liu1,XU Wen-Xie1,2,*
1Research Laboratory of Digestive and 2Research Center of Affiliated Hospital, Yanbian University College of Medicine, Yanji 133000
Abstract:To investigate the relationship between cytoskeleton and hypoosmotic membrane stretch-induced increase in muscarinic current, the role of actin microfilament in hypoosmotic membrane stretch-induced increase of muscarinic current was studied with the whole-cell patch clamp technique in guinea-pig gastric myocytes. In this study, the muscarinic current was induced by carbachol (50 μmol/L) or GTPγS (0.5 mmol/L). The results showed that hypoosmotic superfusate (202 mOsmol/L) increased carbachol-induced current (ICch) by 145±27% and increased GTPγS-induced current by 183±30%; but in the presence of cytochalasin-B (Cyt-B, 20 μmol/L), an actin cytoskeleton disruptor, hypoosmotic membrane stretch increased ICch by 70±6%. However, hypoosmotic membrane stretch induced increase in ICch was potentiated to 545±81% by phalloidin (20 μmol/L), an actin microfilament stabilizer. The results demonstrated that hypoosmotic membrane stretch increased the muscarinic currents induced by carbachol or GTPγS and that the actin microfilament is involved in the process in guinea-pig gastric myocytes.
Key words: muscarinic currents; gastric myocytes; stretch; actin microfilament
微丝在低渗牵张对毒蕈碱电流增加中的作用
王佐妤1, 禹永春1, 崔艺峰1, 李林1, 郭慧淑1, 李在琉1, 许文燮1,2，*
延边大学医学院 1消化生理研究室、2附属医院中心实验室, 延吉 133000
摘要:在急性分离的豚鼠胃窦平滑肌细胞上, 利用膜片钳技术的传统全细胞模式记录离子电流的方法, 探讨微丝在低渗牵张对毒蕈碱电流增加中的作用。当豚鼠胃窦平滑肌细胞的膜电位钳制在-20 mV时, 灌流液中50 μmol/L 卡巴胆碱(carbachol, Cch)或电极内液中0.5 mmol/L GTPγS均可引导毒蕈碱电流(muscarinic current ICch), 低渗牵张(202 mOsmol/L)分别使其增加145±27%和183±30%; 当电极内液中加入20 μmol/L的细胞松弛B (一种微丝骨架的解聚剂)时, 低渗牵张使ICch只增加70±6%; 而电极内液中加入20 μmol/L的鬼笔环肽(一种微丝骨架的稳定剂)则使ICch增加了545±81%。结果表明, 低渗牵张可增加由卡巴胆碱或GTPγS诱导的毒蕈碱电流, 微丝参与调节低渗牵张对豚鼠胃窦平滑肌细胞ICch的增加作用。
关键词: 毒蕈碱电流; 胃窦平滑肌; 牵张; 微丝
中图分类号: Q482