Kubota Kunitsugu, Ohtake Nobuhiro, Ohbuchi Katsuya, Mase Akihito, Imamura Sachiko, Sudo Yuka, Miyano Kanako, Yamamoto Masahiro, Kono Toru, Uezono Yasuhito
Tsumura Research Laboratories, Tsumura & Co., Ibaraki, Japan;
Tsumura Research Laboratories, Tsumura & Co., Ibaraki, Japan; Division of Cancer Pathophysiology, National Cancer Center Research Institute, Tokyo, Japan;
Am J Physiol Gastrointest Liver Physiol. 2015 Apr 1;308(7):G579-90. doi: 10.1152/ajpgi.00114.2014. Epub 2015 Jan 29.
Various colonic motor activities are thought to mediate propulsion and mixing/absorption of colonic content. The Japanese traditional medicine daikenchuto (TU-100), which is widely used for postoperative ileus in Japan, accelerates colonic emptying in healthy humans. Hydroxy-α sanshool (HAS), a readily absorbable active ingredient of TU-100 and a KCNK3/KCNK9/KCNK18 blocker as well as TRPV1/TRPA1 agonist, has been investigated for its effects on colonic motility. Motility was evaluated by intraluminal pressure and video imaging of rat proximal colons in an organ bath. Distribution of KCNKs was investigated by RT-PCR, in situ hybridization, and immunohistochemistry. Current and membrane potential were evaluated with use of recombinant KCNK3- or KCNK9-expressing Xenopus oocytes and Chinese hamster ovary cells. Defecation frequency in rats was measured. HAS dose dependently induced strong propulsive "squeezing" motility, presumably as long-distance contraction (LDC). TRPV1/TRPA1 agonists induced different motility patterns. The effect of HAS was unaltered by TRPV1/TRPA1 antagonists and desensitization. Lidocaine (a nonselective KCNK blocker) and hydroxy-β sanshool (a geometrical isomer of HAS and KCNK3 blocker) also induced colonic motility as a rhythmic propagating ripple (RPR) and a LDC-like motion, respectively. HAS-induced "LDC," but not lidocaine-induced "RPR," was abrogated by a neuroleptic agent tetrodotoxin. KCNK3 and KCNK9 were located mainly in longitudinal smooth muscle cells and in neural cells in the myenteric plexus, respectively. Administration of HAS or TU-100 increased defecation frequency in normal and laparotomy rats. HAS may evoke strong LDC possibly via blockage of the neural KCNK9 channel in the colonic myenteric plexus.
各种结肠运动活动被认为可介导结肠内容物的推进以及混合/吸收。日本传统药物大建中汤（TU-100）在日本被广泛用于治疗术后肠梗阻，它能加速健康人的结肠排空。羟基-α-山椒素（HAS）是TU-100的一种易于吸收的活性成分，是一种KCNK3/KCNK9/KCNK18阻滞剂以及TRPV1/TRPA1激动剂，其对结肠运动的影响已得到研究。通过器官浴中大鼠近端结肠的腔内压力和视频成像来评估运动。通过逆转录聚合酶链反应（RT-PCR）、原位杂交和免疫组织化学研究KCNKs的分布。使用表达重组KCNK3或KCNK9的非洲爪蟾卵母细胞和中国仓鼠卵巢细胞来评估电流和膜电位。测量大鼠的排便频率。HAS剂量依赖性地诱导强烈的推进性“挤压”运动，推测为长距离收缩（LDC）。TRPV1/TRPA1激动剂诱导不同的运动模式。TRPV1/TRPA1拮抗剂和脱敏对HAS的作用没有影响。利多卡因（一种非选择性KCNK阻滞剂）和羟基-β-山椒素（HAS的几何异构体和KCNK3阻滞剂）分别诱导结肠运动，表现为节律性传播波（RPR）和类似LDC的运动。HAS诱导的“LDC”，而非利多卡因诱导的“RPR”，被神经阻滞剂河豚毒素消除。KCNK3和KCNK9分别主要位于纵行平滑肌细胞和肌间神经丛的神经细胞中。给予HAS或TU-100可增加正常大鼠和剖腹手术大鼠的排便频率。HAS可能通过阻断结肠肌间神经丛中的神经KCNK9通道诱发强烈的LDC。
