Abstract: To establish  rat models of  chronic psychological stress and to study the effects of Jiaweisinisan(JWSNS) on gastric emptying rate and small intestinal propulsion ratio,cyclic nucleotide system in rat hypothalamus ( cAMP,CGMP )，and mRNA expressions of gastrin receptor (GASR) in stomach tissue and vasoactive intestinal peptide II receptor ( VIPR2) in jejunal tissue of rat models,and to elucidate the mechanism of JWSNS in effecting stress-induced gastrointestinal dysfunction. Methods 60 rats were randomly divided into normal group,model group,small,middle,big doses of JWSNS  groups,and Xishabilly group,10 in each group.The rat models were set up by chronic psychological stress method,after JWSNS intervention,the gastrointestinal motility was detected,and radioimmunoassay was used to detect the changes of cAMP and cGMPcontents in hypothalamus of rats，and the mRNA expression changes of GASR in stomach tissue and VIPR2 in jejunal tissue of rats were measured with RT-PCR method.
Results  Compared with model group,the contents of hypothalamus cGMP and cAMP in treatment groups were decreased,there were  significant differences (P<0.05or P<0.01);compared with Xishabilly group,the contents of hypothalamus cGMP and cAMP in big dose of JWSNS  group were decreased,there were significant differences(P<0.05　or　P<0.01).Compared with model group,the gastric emptying rate and small intestinal propulsion ratio in treatment groups were significantly increased (P<0.05　or P<0
.01);compared with Xishabilly group,the gastric emptying rate in  big dose of JWSNS group was not significantly increased (P>0.05),and the small intestinal propulsion ratio was increased significantly (P<0.05). Compared with model group,the GASR mRNA expression levels in stomach tissue in treatment groups were increased,and the VIPR2 mRNA expression levels in jejunal tissue were decreased,the differences were statistically significant (P<0.05　or　P<0.01);the GASR mRNA expression levels in middle   and big doses of JWSNS  groups were higher  than that in Xishabilly group (P<0.05 or　P<0.01),and the VIPR2 mRNA expression level in jejunal tissue in  big dose of JWSNS group was lower than that in  Xishabilly group ( P<0.01).
Conclusion The cyclic nucleotide system (cAMP,CGMP) abnormalities can affect the gastrointestinal function and JWSNS can regulate chronic psychological stress response by influencing cyclic nucleotide system,thereby improve the gastrointestinal function，and improve the expressions of VIPR2 and GASR mRNA in stomach and jejunum tissues.
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Key words: Jiaweisinisan, stress, gastrin receptor, vasoactive intestinal peptide Ⅱ receptor, gastrointestinal motility