Abstract: OBJECTIVE:To investigate the regulatory effects of Wei Chang An Pill(WCAP) on enzyme activity and gastrointestinal hormones in the small intestine of rats with compound diarrhea.METHODS:Forty Wistar rats were randomly divided into a control,diarrhea model,and WCAP high,medium,and low dose groups.The control group was not treated,and the model group was administered intragastric distilled water.The WCAP groups were given WCAP suspension,80,60 or 40 mg · kg-1 · d-1,for 4 days.Stool properties were observed.After the experiment,thymus and spleen indices were measured,and the activities of lactate dehydrogenase(LDH),malate dehydrogenase(MDH),and disaccharidase(lactase) in the small intestinal mucous membrane,and levels of substance P(SP) and vasoactive peptide(VIP) in the colon were determined.RESULTS:Compared with the control group,thymus and spleen indices were significantly decreased,LDH,MDH,and disaccharidase activity in the small intestine was decreased,and SP and VIP levels in the colon were significantly increased inthe diarrhea model group.Compared with the model group,thymus and spleen indices were significantly increased,and LDH,MDH,and disaccharidase activity in the small intestine and SP and VIP levels in the colon were significantly decreased in theWCAP medium dose group.CONCLUSION:The diarrhea model rats exhibited pathological changes including atrophy of the thymus and spleen,decreased enzyme activity in the small intestine,and gastrointestinal hormone disturbance.WCAP can increase the activity of intestinal digestive enzymes and regulate gastrointestinal hormones,thereby relieving diarrhea.

Key words: Wei Chang An Pill(胃肠安丸), Diarrhea, Lactate dehydrogenase, Malate dehydrogenase, Disaccharidase, Substance P(SP), Vasoactive peptide(VIP)