Experimental Study On The Expression Of MAP-2, GDNF And S-100 In Colon Of Rats With Slow Transit Constipated By Tiao Zang Shu Mi Tang

Objective: To investigate the effects of Tiao Zang Shu Mi Tang(TZSMT) on intestinal propulsion rate in STC model rat. Examining the expression of microtubule-associated protein 2, glial cell line-derived neurotrophic factor and S-100 protein in colonic enteric nervous system in model rats so as to explore effects and underlying mechanisms on TZSMT in treating STC model rat.Methods: SD rats were randomly divided into control group and model group. Model group was intragastrical administrated with the compound diphenoxylate to establish STC model. While the control group was treated with water. After that,model rats were further divided into model control group, cisapride treatment group, TZSMT low-dose group, TZSMT middle-dose group and TZSMT high-dose group. To measure the intestinal propulsion rate in rats after treatment, and then proximal colon tissue samples were removed. Morphological changes were observed in rat colon nervous system with HE staining, and detected MAP-2, GDNF, S-100 positive expression intensity and semi-quantitative analysis by immunohistochemical methods.Results:(1)Compared with the blank group,vacuole denaturalization was detected in enteric ganglionic cells in the model group. Specifically,the cell volume tended to be smaller, shrunken,slight swelling and uneven staining as well as the amount of neurons decreased. It was significantly improved in other treatment groups except TZSMT high-dose group. Particularly,the TZSMT middle-dose group showed most remarkable effect between these groups.(2)In comparing with the control group, the expression level of MAP-2 and GDNF decreased whereas S- 100 increases in the model group, the difference was statistically significant(P <0.05);(3)There was no statistically significant difference in TZSMT low-dose,TZSMT middle-dose and cisapride treatment group on increase intestinal propulsion rate, S100 reduction and expression increase of MAP-2, GDNF:(P> 0.05); Cisapride treatment group was better than that of TZSMT of high-dose group and the difference was statistically significant(P <0.05); there was no statistically significant difference in TZSMT of low-dose, middle-dose that have considerable effect(P> 0.05); TZSMT of low-dose, middle-dose group were superior to high-dose group and the difference was statistically significant(P <0.05).Conclusion:(1)There has morphological change in STC model rats on colonic enteric nervous system.(2) The expression levels of Colon GDNF and MAP-2 are reduced in STC model rats, suggesting that GDNF and MAP-2 may be involved in the pathogenesis of STC.(3)TZSMT may increase the expression of GDNF and MAP-2. Which tend to repair function in STC rat colon plexus and exert therapeutic effect.(4)TZSMT in low-dose or middle-dose may be the optimal dose for clinical usage.