[Experimental study on the effect of Glycyrrhiza on small intestinal motility in rats]

To investigate the effects of glycyrrhiza decoction on migrating myoelectric complex (MMC) and gastrointestinal hormone in small intestine in rats.

We observed MMC cycle,phase Ill duration,fast wave numbers of phase III of MMC in one minute, fast wave numbers of one cluster in phase III of MMC of small intestine of glycyrrhiza group and control group rats with electrophysiology method, and immunohistochemistry to examine relative content of serotonin (5-HT), substance p(SP) and vasoactive intestinal polypeptide (VIP) in small intestinal chromophil (EC) and myenteric nerve plexus in small intestine of control group and glycyrrhiza group rats.

Compared glycyrrhiza group with control group,we found that glycyrrhiza was able to decrease fast wave numbers in one minute and fast wave numbers in one cluster in phase III of MMC of small intestine (P < 0.05), and evidently extend small intestinal cycle of MMC (P < 0.05), it also shortened the phase III III duration (P < 0.05) or made the phase III of MMC absent. Compared glycyrrhiza group with control group it was indicated that content of 5-HT in small intestinal mucous membrane and myenteric nerve plexus was evidently decreased (P < 0.05), and content of SP in myenteric nerve plexus of small intestine of rats was evidently decreased (P < 0.05), and content of VIP in small intestine of rats was evidently increased (P < 0.05).

Glycyrrhiza is able to inhibit small intestinal motility, this inhibition is related with the amount of 5-HT, SP, VIP secreted by small intestinal mucous membrane of rats.