Experimental Study On The Correlation Between Intestinal Physiochemical Factors And Pathological Changes Of Intestinal Mucosa After Right Hemicolectomy

Objective:The present studies established establish the SD rats model of right hemicolectomy,explored the mechanism of intestinal dysfunction after right hemicolectomy by detecting intestinal mucosal barrier related physiochemical factors,and analyzed its correlation with intestinal mucosal pathological changes.Methods:75 SD rats were divided randomly into three groups:right hemicolectomy group(resection range includes about 5cm terminal ileum,ileocecus,8cm colon and its corresponding mesentery)(Group A,n=25),negative control group(no-treatment)(Group B,n=25),sham operation group(only open and close the abdomen)(Group C,n=25).Relevant data was detected on the day before operation and 1,2,3,4 weeks after recovering from surgery to normal free eating,After that,all rats was executed.(1)the changes of SD rats’ weight was recorded weekly,and the mainfestation of postoperative intestinal dysfunction was observed;(2)20 mg fresh fecal(dry weight)was diluted to 2ml solution,the changes of relative concentration of bile acid、sodium ion and potassium ion was detected in clinical laboratory with automatic biochemistry analyzer;(3)20 mg colonic intestinal contents was diluted to 10 ml solution,the changes of relative osmolarity of osmotic pressure was detected in clinical laboratory with Freezing-point Osmometer;(4)the changes of colonic intestinal pH was detected with pH meter after the colonic intestinal segments was slit along with its mesentery;(5)the histological changes of colonic tissues was assessed with Hematoxylin-Eosin(HE)staining.Results:(1)Within 4 weeks after operation,the body weight had descended markly in Group A,while compared with Group B and Group C(P<0.05),stool frequency increased obviously,and stool became diluted in varying degree,especially in the 1 week.(2)Within 4 weeks after operation,the relative concentration of bile acid in the feces continued to rising in Group A,especially in the 3 week(P<0.05),and had a negative correlation with postoperative colonic intestinal mucosal Histological Index(HI)score(r=-0.89),Group B,C didn’t change significantly.(3)Within 4 weeks after operation,colonic intestinal pH in group A was continuously higher than Group B,C,and had a low correlation with postoperative colonic intestinal mucosal HI score(r=0.12),Group B,C didn’t change significantly.(4)The relative osmolarity of colonic osmotic pressure and the relative concentration of sodium ion,potassium ion in the feces had increased significantly in 1 week after operation in Group A(P<0.05),and had a low correlation with postoperative colonic intestinal mucosal HI score(r=0.04/r=0.14/r=0.45),Group B,C didn’t change significantly.(5)Within 4 weeks after operation,colonic intestinal mucosa showed damage repair process in Group A,of which the damage was most obvious in the 1 week,and colonic intestinal mucosal HI score had increased significantly(P<0.05),Group B,C didn’t change significantly.Conclusion:(1)Within 4 weeks after SD rats of right hemicolectomy,the relative concentration of bile acid in the feces continued to rising,and had a significantly negative correlation with postoperative colonic intestinal mucosal pathological changes.(2)Within 4 weeks after SD rats of right hemicolectomy,the colonic intestinal pH was continuously high,and had a low correlation with postoperative colonic intestinal mucosal pathological changes.(3)Within 1 weeks after SD rats of right hemicolectomy,the relative osmolarity of colonic osmotic pressure and the relative concentration of sodium ion,potassium ion in the feces had increased significantly,and had a low correlation with postoperative intestinal mucosal pathological changes within 4 weeks.