Lee Kyu Pil, Jun Jae Yeoul, Chang In-Youb, Suh Suk-Hyo, So Insuk, Kim Ki Whan
Department of Physiology and Biophysics, Seoul National University College of Medicine, Seoul 110-799, Korea.
Mol Cells. 2005 Dec 31;20(3):435-41.
Classical transient receptor potential channels (TRPCs) are thought to be candidates for the nonselective cation channels (NSCCs) involved in pacemaker activity and its neuromodulation in murine stomach smooth muscle. We aimed to determine the role of TRPC4 in the formation of NSCCs and in the generation of slow waves. At a holding potential of -60 mV, 50 mM carbachol (CCh) induced INSCC of amplitude [500.8+/-161.8 pA (n=8)] at -60 mV in mouse gastric smooth muscle cells. We investigated the effects of commercially available antibodies to TRPC4 on recombinant TRPC4 expressed in HEK cells and CCh-induced NSCCs in gastric smooth muscle cells. TRPC4 currents in HEK cells were reduced from 1525.6+/-414.4 pA (n=8) to 146.4+/-83.3 pA (n=10) by anti-TRPC4 antibody and INSCC amplitudes were reduced from 230.9+/-36.3 pA (n=15) to 49.8+/-11.8 pA (n=9). Furthermore, INSCC in the gastric smooth muscle cells of TRPC4 knockout mice was only 34.4+/-10.4 pA (n=8) at -60 mV. However, slow waves were still present in the knockout mice. Our data suggest that TRPC4 is an essential component of the NSCC activated by muscarinic stimulation in the murine stomach.
经典瞬时受体电位通道（TRPCs）被认为是参与小鼠胃平滑肌起搏活动及其神经调节的非选择性阳离子通道（NSCCs）的候选者。我们旨在确定TRPC4在NSCCs形成和慢波产生中的作用。在-60 mV的钳制电位下，50 mM卡巴胆碱（CCh）在小鼠胃平滑肌细胞中于-60 mV诱导出幅度为[500.8±161.8 pA（n = 8）]的内向非选择性阳离子电流（INSCC）。我们研究了市售的TRPC4抗体对在HEK细胞中表达的重组TRPC4以及对胃平滑肌细胞中CCh诱导的NSCCs的影响。抗TRPC4抗体使HEK细胞中的TRPC4电流从1525.6±414.4 pA（n = 8）降至146.4±83.3 pA（n = 10），并使INSCC幅度从230.9±36.3 pA（n = 15）降至49.8±11.8 pA（n = 9）。此外，在TRPC4基因敲除小鼠的胃平滑肌细胞中，-60 mV时的INSCC仅为34.4±10.4 pA（n = 8）。然而，基因敲除小鼠中仍存在慢波。我们的数据表明，TRPC4是小鼠胃中由毒蕈碱刺激激活的NSCC的重要组成部分。
