RESUMO
OBJECTIVE: To observe the effect of acupuncture on expression of receptor tyrosine kinase (RTK) c-kit in interstitial cells of Cajal (ICCs), carbon monoxide (CO) and heme oxygenase (HO) in colon tissue after colonic anastomosis, so as to explore the mechanism of acupuncture in improving gastrointestinal motility. METHODS: SD rats were randomly devided into control group, model group and acupuncture group. The model was established using colonic anastomosis. Each group was further devided into 3, 5, and 10 d (time-point) subgroups (n=10 in each). Acupuncture was applied to acupuncture group at bilateral "Zusanli" (ST 36), "Sanyinjiao" (SP 6) and "Taichong" (LR 3) for 15 min, once daily after modeling. The first defecation time was recorded, and the intestinal propulsive rate was measured. The expression of c-kit in colon tissue was detected by immunohistochemistry. The content of CO, the activities of HO-1 and HO-2 in colon tissue were detected by biochemical method and ELISA, respectively. RESULTS: Compared to the control group, the intestinal propulsive rate and the expression level of c-kit in ICCs were decreased in the model group(P<0.05), the content of CO and the activity of HO-1 were increased in model 3 d and 5 d subgroups(P<0.05), the activity of HO-2 was increased in model 3 d subgroup(P<0.05), while the opposite results appeared in model 5 d and 10 d subgroups(P<0.05). Compared to the model group, the first defecation time was shortened (P<0.05), the intestinal propulsive rate and the expression level of c-kit in ICCs were increased in the acupuncture group (P<0.05), the content of CO and the activity of HO-1 were decreased in acupuncture 3 d and 5 d subgroups(P<0.05), the activity of HO-2 was decreased in acupuncture 3 d subgroup(P<0.05), while the opposite result appeared in acupuncture 10 d subgroup(P<0.05). Compared to the 3 d subgroup, the intestinal propulsive rate and the expression level of c-kit in ICCs were increased, the content of CO, the activities of HO-1 and HO-2 were decreased in both model and acupuncture 5 d subgroups (P<0.05). In model 10 d subgroup, the intestinal propulsive rate and the expression level of c-kit in ICCs were increased, the content of CO and the activity of HO-1 were decreased in comparison with the model 5 d subgroup(P<0.05). CONCLUSIONS: Acupuncture can improve postoperative gastrointestinal motility by declining CO content and HO-1 and HO-2 activity in colon tissue, and promoting ICCs restoration.