Department of Sasang Constitutional Medicine, College of Korean Medicine, Kyung-hee University, Seoul 130-701, South Korea.
World J Gastroenterol. 2013;19(14):2249-55. doi: 10.3748/wjg.v19.i14.2249.
To investigate the effects of Lizhong Tang, an herbal product used in traditional Chinese medicine, on mouse small intestine interstitial cells of Cajal (ICCs).
Enzymatic digestions were used to dissociate ICCs from mouse small intestine tissues. The ICCs were morphologically distinct from other cell types in culture and were identified using phase contrast microscopy after verification with anti c-kit antibody. A whole-cell patch-clamp configuration was used to record potentials (current clamp) from cultured ICCs. All of the experiments were performed at 30-32 °C.
ICCs generated pacemaker potentials, and Lizhong Tang produced membrane depolarization in current-clamp mode. The application of flufenamic acid (a nonselective cation channel blocker) abolished the generation of pacemaker potentials by Lizhong Tang. Pretreatment with thapsigargin (a Ca²⁺-ATPase inhibitor in the endoplasmic reticulum) also abolished the generation of pacemaker potentials by Lizhong Tang. However, pacemaker potentials were completely abolished in the presence of an external Ca²⁺-free solution, and under this condition, Lizhong Tang induced membrane depolarizations. Furthermore, When GDP-β-S (1 mmol/L) was in the pipette solution, Lizhong Tang still induced membrane depolarizations. In addition, membrane depolarizations were not inhibited by chelerythrine or calphostin C, which are protein kinase C inhibitors, but were inhibited by U-73122, an active phospholipase C inhibitors.
These results suggest that Lizhong Tang might affect gastrointestinal motility by modulating pacemaker activity in interstitial cells of Cajal.
研究中药理中汤对小鼠小肠 Cajal 间质细胞（ICCs）的影响。
采用酶消化法从小鼠小肠组织中分离 ICCs。在培养过程中，ICCs 的形态与其他细胞类型明显不同，并用抗 c-kit 抗体验证后，通过相差显微镜进行鉴定。采用全细胞膜片钳记录培养 ICCs 的电位（电流钳模式）。所有实验均在 30-32℃下进行。
ICCs 产生起搏电位，理中汤在电流钳模式下产生膜去极化。应用氟芬那酸（一种非选择性阳离子通道阻滞剂）可消除理中汤产生的起搏电位。预先用 thapsigargin（内质网中的 Ca²⁺-ATP 酶抑制剂）处理也可消除理中汤产生的起搏电位。然而，在不存在外 Ca²⁺的溶液中，起搏电位完全被消除，在此条件下，理中汤诱导膜去极化。此外，当 GDP-β-S（1 mmol/L）存在于管内液中时，理中汤仍可诱导膜去极化。另外，膜去极化不受蛋白激酶 C 抑制剂 chelerythrine 或 calphostin C 的抑制，但可被活性磷脂酶 C 抑制剂 U-73122 抑制。
这些结果表明，理中汤可能通过调节 Cajal 间质细胞的起搏活性来影响胃肠动力。
