Abstract: To study the effect of Capsaicin (Cap) with different low dosages on the gastric motility,transient receptor potential vanilloid1 (TRPV1) and neurotensin (NT) in gastric antrum and brain tissue of rat with chronic stress (CUMS) and to explore its mechanism.The experimental rat model of gastric motility disorders was replicated by chronic unpredictable mild stress (CUMS).The CUMS model rats were treated with different low dosages of Cap 0.04 mg/kg,0.4 mg/kg,4 mg/kg within two weeks.The gastric emptying rate of phenol red was used to reflect the gastric motility.The TRPV1 and NT content in gastric antrum and brain were measured by ELISA.The results showed that the gastric emptying rate of phenol red of CUMS model group was significantly lower than that of normal group.And after treating with different dosages of Cap,the gastric emptying rate of phenol red of each group were higher than that of CUMS model group (P<0.05).Moreover,with the increasing doses of Cap,the gastric emptying rate decreased.In addition,the increased expression of TRPV1 and NT were depended on the dosage of Cap.It can clearly be seen that the three doses of Cap showed an improve effect on the gastric motility disorders rats with CUMS,especially the 0.04 mg/kg dosage group.These results demonstrated that the low dosage of Cap might have an improve effect on the gastric motility disorders rats with CUMS,and one of the mechanisms was that Cap can regulate the expressions of TRPV1 and NT.

Key words: Capsaicin, gastric motility, TRPV1, NT