纳豆枯草杆菌培养滤液对家兔离体肠平滑肌的作用

目的观察纳豆枯草杆菌培养滤液（culture filtrate，CF）对家兔离体肠平滑肌的作用，并初步探讨其作用机制。方法制备兔离体回肠标本，分别记录肠平滑肌的正常收缩张力和收缩频率作为给药前对照，然后按累积剂量分别加入CF小剂量（每次0．2mL）、CF大剂量（每次0．5mL）、肉汤（每次0．5mL），给药间隔3min，共给药8次，并描记收缩曲线。观察不同剂量cF对肠平滑肌的作用。另取肠段按毛果芸香碱、CF或阿托品、再毛果芸香碱的顺序给药，观察CF对M胆碱受体的作用。结果CF小剂量组在累积给药达1．6mL时，CF大剂量组在累积给药达3．5mL和4．0mL时，兔离体肠平滑肌收缩张力下降，与给药前比较差异有统计学意义（P〈0．05），其余各点差异均无统计学意义（P〉0．05）。CF小剂量组在累积给药达1．2、1．4、1．6mL时，CF大剂量组在累积给药达4．0mL时，兔离体肠平滑肌收缩频率明显降低，与给药前比较差异有统计学意义（P〈0．05或P〈0．01），其余各点差异均无统计学意义（P〉0．05）。CF或阿托品可明显对抗毛果芸香碱引起的兔离体肠平滑肌收缩张力的增加（P〈0．05或P〈0．01），同时CF还能使其收缩频率明显减少（P〈0．01）。结论纳豆枯草杆菌CF能明显抑制兔离体肠平滑肌蠕动，其作用机制可能与阻断M胆碱受体有关。

Effects of culture filtrate of Bacillus subtilis natto on isolated intestinal smooth muscle of rabbits

Objective To observe the effects of culture filtrate （CF） of Bacillus subtilis natto on isolated intestinal smooth muscle of rabbits, and discuss preliminarily its mechanism. Methods The isolated ileum samples of rabbits were prepared. The contractive force and frequency of intestinal smooth muscle were recorded as the normal control. Then low-dose CF （0.2 mL per time） , high-dose CF （0.5 mL per time） , and broth （0.5 mL per time） were added respectively by an accumulative dose to culture media （ at an interval of 3 rain, total 8 times） and the contraction curves were recorded. The effects of various doses of CF on isolated intestinal smooth muscle were observed. The effect of CF on M cholinoeeptor was observed by adding in order pilocarpine, atropine or CF, and pilocarpine. Results When low-dose CF were continuously added to 1.6 mL, and high-dose CF to 3.5 mL and 4.0 mL, the contractive force of the intestinal smooth muscle was reduced. Compared with the data before administration, the differences were significant （P 〈 O. 05）. When low-dose CF were continuously added to 1.2 mL, 1.4 mL, and 1.6 mL, and high-dose CF to 4.0 mL, the contraction frequency was obviously lowered, and there were significant differences compared with the data before administration （ P 〈 0. 05 or P 〈 0. 01 ）. CF or atropine inhibited pilocarpine-induced increase of contractive force （ P 〈 0.05 or P 〈 0.01 ）. The CF also reduced contraction frequency significantly （P 〈 0. 01 ）. Conclusion CF of Bacillus subtilis natto may obviously inhibit the peristalsis of intestinal smooth muscle of rabbits possibly by blocking M-cholinoceptor.