[维生素K3通过钙激活钾通道对豚鼠结肠平滑肌收缩活动的影响]

[Effects of vitamin K3 on the contractile activity of the colonic smooth muscles of guinea pig through the calcium activated potassium channel].

作者信息

Li Jun, Luo He-sheng, He Xiao-gu

机构信息

Department of Gastroenterology, People's Hospital of Wuhan University, Wuhan 430060, China.

出版信息

Zhonghua Yi Xue Za Zhi. 2006 Jul 25;86(28):1981-4.

PMID:17064596

Abstract

OBJECTIVE

To study the mechanism of relaxation of gastrointestinal smooth muscles by vitamin K(3).

METHODS

Stripes of proximal colon were collected from guinea pigs. Suspension of single cells was created from these stripes. TD-112S transducer was used to measure the contraction of the stripes stimulated by vitamin K(3) of the concentrations of 40, 100, 400, and 800 micromol/L respectively. The Ca(2+)-activated K(+) current [IK(Ca)] of the cytomembrane of the colon smooth muscle was recorded with an EPC 10 amplifier under conventional whole cell patterns.

RESULTS

The contraction frequencies of the muscle stripes stimulated by vitamin K(3) of the concentrations of 40, 100, 400, and 800 micromol/L were 79% +/- 4%, 58% +/- 5%, 33% +/- 4%, and 12% +/- 3% respectively of that of the control group (all P < 0.01), and the contraction strength was reduced to 77% +/- 10%, 54% +/- 7%, 30% +/- 6%, and 11% +/- 4% respectively (all P < 0.01). The IK((Ca)) of the cytomembrane of the colon smooth muscle at the voltage of +60 mV was increased to 120% +/- 18%, 149% +/- 12%, 197% +/- 19%, and 223% +/- 14% respectively (all P < 0.01).

CONCLUSION

Vitamin K(3) inhibits the contractile activity of the colonic muscle stripes and increases the IK(Ca) of single myocytes concentration-dependently. The mechanism is activation of the Ca(2+)-activated K(+) channel, thus promoting the potassium efflux.

摘要

目的

研究维生素K(3)对胃肠平滑肌舒张的作用机制。

方法

取豚鼠近端结肠肌条，制成单细胞悬液。用TD-112S换能器分别测定40、100、400和800 μmol/L维生素K(3)刺激肌条的收缩情况。在传统全细胞模式下，用EPC 10放大器记录结肠平滑肌细胞膜的钙激活钾电流[IK(Ca)]。

结果

40、100、400和800 μmol/L维生素K(3)刺激肌条的收缩频率分别为对照组的79%±4%、58%±5%、33%±4%和12%±3%（均P<0.01），收缩强度分别降至77%±10%、54%±7%、30%±6%和11%±4%（均P<0.01）。结肠平滑肌细胞膜在+60 mV电压下的IK((Ca))分别增加至120%±18%、149%±12%、197%±19%和223%±14%（均P<0.01）。