Effects of Yiqi Kaimi Recipe on gastrointestinal motility and neuropeptides in rats with colonic slow transit constipation

OBJECTIVE: To observe the effects of Yiqi Kaimi Recipe (YQKMR), a traditional Chinese compound medicine, on gastrointestinal motility and neuropeptides in rats with colonic slow transit constipation. METHODS: Eighty specific pathogen free rats were included, and there were sixty rats with slow transit constipation (STC) and twenty normal rats. Sixty rats with STC were randomly divided into untreated group, cisapride-treated group and YQKMR-treated group, and twenty normal rats were allocated to normal control group. Percentage of carbon propelling, contraction frequency and amplitude of the muscle segments in vitro, and expressions of nitric oxide synthase-1 (NOS1) and substance P proteins were observed. RESULTS: Compared with the normal control group, the percentage of carbon propelling, and the contraction frequency and amplitude of the muscle segments in the untreated group decreased obviously (P<0.05) The percentage of carbon propelling, and the contraction frequency and amplitude of the muscle segments in the YQKMR-treated group and cisapride-treated group were higher than those in the untreated group (P<0.05). The expression of NOS1 protein in the untreated group was higher than that in the normal control group, YQKMR-treated group and cisapride-treated group. However, there were no significant differences between the YQKMR-treated group and the normal control group (P>0.05). The expression of substance P protein in the untreated group was lower than that in the normal control group, and there was no significant difference between the YQKMR-treated group and the normal control group too (P>0.05). CONCLUSION: Yiqi Kaimi Recipe could promote colon motility by increasing the contraction frequency and amplitude of the smooth muscle, and this may be due to its effect of regulating the expressions of NOS1 and substance P proteins in the enteric plexus.