Changes Of Amount Of Interstitial Cells Of Cajal And Expression Of SCF/c-kit In The Process Of Cathartic Colon Induced By Emodin In Mice

Objective: To establish a mouse cathartic colon model induced by emodin and to detect the dynamic changes of colonic transit function, colonic myoelectric activity in vivo and gross observation and HE staining of mouse colon specimens and to investigate dynamic changes of amount of interstitial cells of Cajal, and expression of SCF/c-kit in the process of induced by emodin in mice.Methods: A modified cathartic colon mouse model induced by emodin was set up. 72 healthy male Kunming(KM) mice were randomly divided into the control group(group C) and persistant application group(group P). At different time points as designed the dynamic changes of colonic electromyography(EMG) in vivo were detected by biological and functional experimental system; Colonic transit function were examined by activated charcoal moving method; Morphological changes of colon in mice were gross observed in vivo with naked eye and morphological changes of colon specimens in mice were observed by HE staining; Frozen section immunofluorescence was used to detect dynamic changes of amount of ICC; Serum concentrations of SCF were examined by ELISA; Western blot was employed for observation of expression of SCF/c-kit in colon.Results:(1) A modified cathartic colon mouse model induced by emodin monomer was successfully established for 12 W. 2W after treatment, group P appeared to be worse hair shiny, slower weight gain than that of group C. After the model completed group P gained smaller size of mice body and less weight compared with group C. 2 mice of group P died during 12 W.(2) Changes in mouse colonic electromyography(EMG): 2W after treatment,frequency, amplitude and frequency, amplitude coefficient of variation of EMG in group P did not change significantly than that in group C. 6W after treatment, frequency(group C: 19.33±1.74times/min, group P: 10.85±0.92times/min), amplitude(group C: 0.37±0.01 m V, group P: 0.22±0.02 m V) of EMG in group P decreased significantly than that in group C(P <0.05) and frequency, amplitude coefficient of variation of EMG in group P was significantly higher than that in group C. 12 W after treatment,frequency, amplitude of EMG in group P were at a lower level compared with group C.(3) Changes in colonic transit function: colonic transit function were examined by activated charcoal moving method. 2-4W after treatment, statistical averages of colonic transit function measurement in group P(68.8±1.2%)increased significantly(P <0.05) than that in group C(59.4±1.9%). 6-8W after treatment,statistical averages of colonic transit function measurement in group P(50.4±2.4%)decreased significantly(P <0.05) than that in group C(57.4±0.9%). Meanwhile 10W(group P: 60.5±0.9%) after treatment, statistical averages of colonic transit function measurement in group P decreased no significantly than that in group C. but 12 W after treatment,statistical averages of colonic transit function measurement in group P(39.6±1.2%) decreased significantly(P <0.05) than that in group C(58.9±0.9%).(4) Gross observed in vivo and HE staining: 12 W after treatment, the weight of mouse?length and diameter of entire colon in group P were all reduced compared with group C with gross observed in vivo with naked eye; 2W after treatment, colon in group P appeared to be thinner colonic mucosa, more severe mucosal structure disorder, shallower pouch mucosa and no significant change in muscular layer compared with group C; 12 W after treatment, colon in group P showed mucosa edema, mucosal epithelial shedding phenomenon, submucosa inflammatory cell infiltration, no significant changes in muscular layer compared with group C.(5) Changes of amount of colon ICC: Frozen section immunofluorescence was used to detect dynamic changes of amount of ICC; 6W after treatment, statistical averages of frozen section immunofluorescence measurement in group P(7.7±1.0%) decreased significantly(P <0.05) than that in group C(10.9±0.7%); 10-12 W after treatment, statistical averages of frozen section immunofluorescence measurement in group P(3.2±0.6%) higher reduced significantly(P <0.05) than that in group C(10.9±0.7%). Amount of ICC in group C had no significant dynamic changes during 12 W.(6) Changes of serum concentrations of SCF: Serum concentrations of SCF were examined by ELISA. 4W after treatment, statistical averages of serum concentrations of SCF in group P(71.2±2.5pg/ml) decreased significantly(P <0.05) than that in group C(81.3±2.1pg/ml); 6W after treatment, statistical averages of serum concentrations of SCF in group P(55.8±1.9pg/ml) higher reduced significantly(P <0.05) than that in group C(80.4±3.0pg/ml). Serum concentrations of SCF in group C had no significant dynamic changes during 12 W.(7) Changes of expression of c-kit in colon tissue: Western blot was employed for observation of expression of c-kit in colon. 4W after treatment(group P / group C :0.82±0.03), statistical averages of expression of c-kit in group P decreased than that in group C; 8W after treatment t(group P / group C : 0.65±0.04), statistical averages of expression of c-kit in group P higher reduced significantly(P <0.05) than that in group C. Expression of c-kit in group C had no significant dynamic changes during 12 W.Conclusion: 1. A modified cathartic colon mouse model induced by rhubarb extract monomer emodin, which have a high purity and a single component, was successfully established. The model could be controllability and repeatability higher. 2. In the early stage of formation of cathartic colon induced by emodin, colonic transit function significantly accelerated due to the changes of colonic mucosa. but in the later stage of formation of cathartic colon induced by emodin, colonic transit function significantly slowed due to the changes of colonic mucosa and muscular amount of ICC. It appears a fluctuation.3. In the process of cathartic colon, the amount of colonic ICC showed a slow decline during 12W; the changes of SCF were earlier than that of c-kit. Thus it validate the SCF/c-kit signaling pathway is fundamental for regulating proliferation of ICC indeed.