豚鼠胆固醇结石形成中胃肠移行性复合波与胆酸池大小的变化

目的研究豚鼠在胆固醇结石形成中胃肠移行性复合波（MMC）与胆酸池大小的变化.方法75只豚鼠分别给予正常饮食8周,1%胆固醇饮食2、4、8周,胆固醇加维生素C饮食8周.喂养结束后,评估胆囊动力并将4对电极植入胃窦、十二指肠、空肠、回肠.7 d后,记录MMC并测量胆酸池大小.结果胆固醇喂养后,胆囊动力在4周与8周组下降.胆酸池在4周组减小42.75%（P＜0.05）,8周组减小57.24%（P＜0.05）.与对照组相比,MMC以十二指肠起源为主,周期延长（4周组1.32倍,P＜0.05;8周组1.44倍,P＜0.05）,而波幅降低（4周组降低40.91%,P＜0.05;8周组降低60.17%,P＜0.05）.加维生素C引起的变化与胆固醇喂养的2周组相似.结论高胆固醇饮食抑制MMC并减小胆酸池,与损伤的胆囊动力一起导致胆固醇结石形成.

Changes of gastrointestinal myoelectric activity and bile acid pool during cholesterol gallstone formation in guinea pigs

OBJECTIVE: To investigate the changes of gastrointestinal migrating myoelectric complex (MMC) and bile acid pool size during cholesterol gallstone formation in guinea pigs. METHODS: Seventy-five guinea pigs were randomized into 5 equal groups and given normal diet for 8 weeks, 1% cholesterol diet for 2, 4, and 8 weeks, and cholesterol diet with Vitamin C for 8 weeks, respectively. At the end of the feeding period, the gallbladder motility was assessed by deploying 4 bipolar silver electrodes on the antrum, duodenum, jejunum and ileum. Seven days later, MMC was recorded and the total bile acid pool size measured according to the isotope dilution method. RESULTS: After cholesterol feeding, the gallbladder motility declined in 4- and 8-week groups, which showed a reduction of bile acid pool size by 42.75% (P<0.05) and 57.24% (P<0.05), respectively. Compared to the control group, MMCs started mostly in the duodenum. MMC cycle duration was prolonged in the duodenum by 1.32 times in 4-week group (P<0.05) and 1.44 times in 8 week group (P<0.05) whereas MMC amplitude was lowered in the duodenum by 40.91% in 4-week group (P<0.05) and 60.17% in 8 week group (P<0.05). Supplementation of vitamin C caused changes in MMC similar to those observed in the guinea pigs of 2-week group. CONCLUSIONS: High-cholesterol diet inhibits MMC activity and reduces bile acid pool size in guinea pigs, which, along with impairment of the gallbladder motility, contributes to the formation of cholesterol stone, whereas vitamin C supplement in the diet may help prevent cholelithiasis.