Cholecystectomy in patients with normal gallbladder function did not alter characteristics in duodenal motility which was not correlated to size of bile acid pool

Relationship between entero-hepatic bile acid circulation and interdigestive migrating myoelectrical activity in rats

AIM: To investigate the effects of entero-hepatic bile acid circulation on the inter-digestive migrating myoelectrical complex (MMC) in rats.

METHODS: Thirty-two rats were divided into four groups. Three pairs of bipolar silver electrodes were chronically implanted in the antrum, duodenum and jejunum. Three groups of them were ligated around the upper part of common bile duct (CBD). The experiments were performed in conscious and fasting state. The gastrointestinal myoelectrical activity was recorded. Ursodeoxycholic acid (UDCA) and saline were then perfused into stomachs of two groups with CBD obstruction and the effects of them on the MMC were observed.

RESULTS: A typical pattern of MMC was observed in normal fasting rats. MMC of antral and duodenal origin disappeared temporarily in earlier stage of CBD obstruction. While MMC of jejunum origin appeared. increased MMC cycle duration was seen after 4 d in rats with CBD obstruction. The MMC after CBD obstruction was characterized by an increased duration of phase II-like activity and decreased duration of phase I & III activity. Perfusion into stomachs with UDCA resulted in a shorter MMC cycle duration and a longer duration of phase III of duodenal origin compared to the normal group.

CONCLUSION: Entero-hepatic bile acid circulation initiates inter-digestive MMC of duodenal origin.

Changes of gastrointestinal myoelectric activity and bile acid pool size after cholecystectomy in guinea pigs

AIM: To investigate the bile acid pool size after cholecystectomy whether or not correlated to the gastrointestinal migrating myoelectric complex (MMC) in guinea pigs.

METHODS: Gallbladder motilities were assessed before cholecystectomy. Furthermore, we continuously monitored interdigestive gastrointestinal motilities using bipolar electrodes in conscious guinea pigs before and after surgery at 4 wk in standard diet group and high cholesterol diet (cholesterol gallstone) group. Total bile acid pool sizes were measured by isotope dilution method at meantime.

RESULTS: After cholecystectomy, there were parallel falls in duration of phase I, II, III and MMC cycle duration but increase in amplitude in the guinea pigs with normal gallbladder function, and in the guinea pigs with cholesterol stones. However, There were not significantly differences. On the other hand, the bile acid pool was definitely small in the GS guinea pigs compared to normal guinea pigs and became slightly smaller after cholecystectomy. Similarly, bile acid in gallbladder bile, fecal bile acid was slightly increased in GS guinea pigs after cholecystectomy, to the same degree as normal. These differences, however, were not significant.

CONCLUSION: It is concluded that in the guinea pigs with normal gallbladder function, and in the guinea pigs with cholesterol stones: (1) Cholecystectomy produce a similar but less marked trend in bile acid pool; and (2) MMC are linked to enterohepatic circulation of bile acids, rather than surgery, which is consistent with changes of the bile acid pool size. As a result, gastrointestinal dyskinesia is not involved in occurrence of postchole-cystectomy syndrome.

Effects of motilin and ursodeoxycholic acid on gastrointestinal myoelectric activity of different origins in fasted rats

AIM: To investigate gastrointestinal migrating myoelectric complex (MMC) and the effects of porcine motilin and ursodeoxycholic acid (UDCA) on MMC of gastrointestinal tract of different origins in fasted rats.

METHODS: Three bipolar silver electrodes were chronically implanted on the antrum, duodenum and jejunum. Seven days later 24 experimental rats were divided into 2 groups. One group was injected with porcine motilin via sublingual vein at a dose of 20 μg/kg, the other group was perfused into stomach with UDCA. The gastrointestinal myoelectric activity was recorded 1 h before and 2 h after the test substance infusions into the rats.

RESULTS: In all fasted rats a typical pattern of MMC was observed. Among the totally 68 activity fronts recorded in fasted rats under control, 67% started in duodenum, and 33% in antrum. MMC cycle duration and duration of phase III of antral origin were longer than those of duodenal origin. Administration of 20 μg/kg porcine motilin induced a premature antral phase III of antral origin. But perfusion into stomach with UDCA resulted in shorter MMC cycle duration, longer duration of phase III of duodenal origin, which were followed with shorter cycle duration and duration of antral phase III.

CONCLUSION: In fasted rats, MMC could originate from antrum and duodenum respectively. The characteristics of MMC of different origins may contribute to the large variations within subjects. The mechanisms of different origins of phase III may be different. Porcine motilin and UDCA could affect MMC of different origins of the gastrointestinal tract in fasted state, respectively.

Review article: gall-bladder motility after intestinal surgery

There is a close relationship in humans between gall-bladder motility and gastrointestinal motility during the fasting state, as well as in the post-prandial period. Only a minority of publications take this relationship into account in the description of biliary dysmotility after various surgical procedures. Most publications deal with post-prandial gall-bladder motility or with stimulation of gall-bladder contraction from various prokinetic drugs or gastrointestinal hormones. Impaired gall-bladder motility has been demonstrated after Billroth II gastric resection, pyloroplasty and colectomy, but the epidemiological data on the risk of gallstone formation in these patients are too scarce and equivocal to recommend prophylactic cholecystectomy. Future studies on gall-bladder motility after surgical procedures should include measurements of gall-bladder motility during the fasting state, as well as in the post-prandial period. The measurements should be related to the migrating motor complexes, and this necessitates a simultaneous recording of gastrointestinal motility.