Effect of the ginsenoside Rb1 on the spontaneous contraction of intestinal smooth muscle in mice  

作　　者：Lei Xu Sui-Ping Huang 

机构地区：[1]Scientific Research Station for Post-doctoral Studies,Post-doctoral Research Centre, Zhongshan Affiliated Hospital,Guangzhou University of Traditional Chinese Medicine, Zhong-shah 528400, Guangdong Province, China [2]Department of Gastroenterology, GuangdongProvincial Traditional Chinese Medicine Hospital, Ersha IslandBranch, Guangzhou 510405, Guangdong Province, China

出　　处：《World Journal of Gastroenterology》2012年第38期5462-5469,共8页世界胃肠病学杂志（英文版）

基　　金：Supported by The National Natural Science Foundation of China, No. 30873328;The State Administration of Traditional Chinese Medicine of the People’s Republic of China, No. 06-075930

摘　　要：AIM: To investigate the effect and the possible mechanism of ginsenoside Rb1 on small intestinal smooth muscle motility in mice. METHODS: Intestinal smooth muscle strips were isolated from male ICR mice (5 wk old), and the effect of ginsenoside Rb1 on spontaneous contraction was recorded with an electrophysiolograph. The effect of ginsenoside Rb1 on ion channel currents, including the voltage-gated K + channel current (IK V ), calcium-activated potassium channel currents (IK Ca ), spontaneous transient outward currents and ATP-sensitive potassium channel current (IK ATP ), was recorded on freshly isolated single cells using the whole-cell patch clamp technique. RESULTS: Ginsenoside Rb1 dose-dependently inhibited the spontaneous contraction of intestinal smooth muscle by 21.15% ± 3.31%, 42.03% ± 8.23% and 67.23% ± 5.63% at concentrations of 25 μmol/L, 50 μmol/L and 100 μmol/L, respectively (n=5,P<0.05). The inhibitory effect of ginsenoside Rb1 on spontaneous contraction was significantly but incompletely blocked by 10 mmol/L tetraethylammonium or 0.5 mmol/L 4-aminopyridine, respectively (n=5, P<0.05). However, the inhibitory effect of ginsenoside Rb1 on spontaneous contraction was not affected by 10 μmol/L glibenclamide or 0.4 μmol/L tetrodotoxin. At the cell level, ginsenoside Rb1 increased outward potassium currents, and IK V was enhanced from 1137.71 ± 171.62 pA to 1449.73 ± 162.39 pA by 50 μmol/L Rb1 at +60 mV (n=6, P<0.05). Ginsenoside Rb1 increased IK Ca and enhanced the amplitudes of spontaneous transient outward currents from 582.77 ± 179.09 mV to 788.12 ± 278.34 mV (n=5, P<0.05). However, ginsenoside Rb1 (50 μmol/L) had no significant effect on IK ATP (n=3, P<0.05). CONCLUSION: These results suggest that ginsenoside Rb1 has an inhibitory effect on the spontaneous contraction of mouse intestinal smooth muscle mediated by the activation of IK V and IK Ca , but the K ATP channel was not involved in this effect.AIM： To investigate the effect and the possible mechanism of ginsenoside Rb1 on small intestinal smooth muscle motility in mice. METHODS： Intestinal smooth muscle strips were isolated from male ICR mice （5 wk old）, and the effect of ginsenoside Rb1 on spontaneous contraction was recorded with an electrophysiolograph. The effect of ginsenoside Rb1 on ion channel currents, including the voltage-gated K ＋ channel current （IK V ）, calcium-activated potassium channel currents （IK Ca ）, spontaneous transient outward currents and ATP-sensitive potassium channel current （IK ATP ）, was recorded on freshly isolated single cells using the whole-cell patch clamp technique. RESULTS： Ginsenoside Rb1 dose-dependently inhibited the spontaneous contraction of intestinal smooth muscle by 21.15% ± 3.31%, 42.03% ± 8.23% and 67.23% ± 5.63% at concentrations of 25 μmol/L, 50 μmol/L and 100 μmol/L, respectively （n=5,P〈0.05）. The inhibitory effect of ginsenoside Rb1 on spontaneous contraction was significantly but incompletely blocked by 10 mmol/L tetraethylammonium or 0.5 mmol/L 4-aminopyridine, respectively （n=5, P〈0.05）. However, the inhibitory effect of ginsenoside Rb1 on spontaneous contraction was not affected by 10 μmol/L glibenclamide or 0.4 μmol/L tetrodotoxin. At the cell level, ginsenoside Rb1 increased outward potassium currents, and IK V was enhanced from 1137.71 ± 171.62 pA to 1449.73 ± 162.39 pA by 50 μmol/L Rb1 at ＋60 mV （n=6, P〈0.05）. Ginsenoside Rb1 increased IK Ca and enhanced the amplitudes of spontaneous transient outward currents from 582.77 ± 179.09 mV to 788.12 ± 278.34 mV （n=5, P〈0.05）. However, ginsenoside Rb1 （50 μmol/L） had no significant effect on IK ATP （n=3, P〈0.05）. CONCLUSION： These results suggest that ginsenoside Rb1 has an inhibitory effect on the spontaneous contraction of mouse intestinal smooth muscle mediated by the activation of IK V and IK Ca , but the K ATP channel was not involved in this effect.

关 键 词：Ginsenoside Rb1 Intestinal smooth muscle Intestinal smooth muscle cell Potassium channel Spontaneous contraction Whole-cell patch clamp technique 

分 类 号：Q95-331[生物学—动物学] O629.13[理学—有机化学]