Study On The Expression Of PAR-2 In Rats Model With Irritable Bowel Syndrome

Objective:To establish different types of irritable bowel syndrome (IBS) animal models, and then used immunohistochemical detection each rat PAR-2 expression of bowel mucosa, understanding the different IBS model of rats in the intestinal mucosa PAR-2 expression differences, to further explore IBS visceral sensitiity possible pathogenesis.Methods:Adult male SD rats only 30 were randomly divided into constipation-predominant irritable bowel syndrome (C-IBS),Diarrhea-predominant irritable bowel syndrome (D-IBS) and normal controls and were Each group of 10 only, use cold saline irrigation stomach manufacture C-IBS animal model, adopt Instillation of acetic acid and restraint stress manufacturing D-IBS animal model. Each group is using colorectal distention (CRD) evaluate visceral sensitivity and examine each rat droppings characters and gastrointestinal through time, Meanwhile histological examination of intestinal tissue to evaluate the histological changes,Then use immunohisto-chemical method in detecting PAR-2 different subtypes of IBS group and the control group in the rat model of bowel mucosa tissue of expression. And the statistical analysis, Understanding the relationship PAR-2 expression and subsets of IBS group.Results:(1) Under the rectum expansion stimulating, threshold value of abdominal construction(TVAC) of colorectal distention in D-IBS group obviously less than control group and C-IBS group (P< 0.05). In 0.8,1.2,1.6mL capacity expansion, The contraction frequency of the abdo-minal muscale in D-IBS group was singnificantly enhanced as compared with that in C-IBS and blank control group (P< 0.05). threshold value of abdominal construction of colorectal distention in C-IBS group obviously higher than control group and D-IBS group (P<0.05). in low capacity expands (0.8 mL), The contraction frequency of the abdominal muscale in C-IBS group was singnificantly reduced as compared with that in D-IBS and blank control group, Difference was statistically significant(P<0.05, table 2).(2)We detected Feces traits in the rats of mode group and found:during stress period (3 h) Feces of D-IBS group is soft or paste,the amount and weight of the feces were higher markedly than control group(P< 0.01), water ratio of the feces were higher than control group(P< 0.05), the time before the first melena defecation in D-IBS group was significantly shorter than that in C-IBS group and control group(P< 0.05). the amount and weight of the feces in C-IBS group during 12 hours were lower markedly than control group(P< 0.01), water ratio of the feces were lower than control group(P< 0.05), the time before the first melena defecation in C-IBS group was significantly longer than D-IBS (P< 0.05, tablel). (3) Colon histological analysis showed that each rat colonic mucosal no significant pathological changes, accord with functional gastroenterol ogical characteristic (figure 1,2,3). (4) PAR-2 positive cells of D-IBS group is crowded, Its Integral optical density(IOD) value is 58.69±8.422, while Integral optical density value of C-IBS group is 33.2±4.237, Integral optical density value of control group is 29.5±3.206. the number of PAR-2 positive cell in colon tissue of rats of the D-IBS group was notably larger than that in C-IBS and control group (P<0.05), but no obvious difference existed between C-IBS and control group (P>0.05, see chart 4,5,6, table 3)Conclusions:(1)Rat model of IBS was established by Instillation of acetic acid plus restraint stress and cold saline irrigation stomach Consistent with visceral hypersensitivity of IBS, and histological analysis showed that the model rats of colon tissue were no significant pathological changes. and can be used for Experimental studies of IBS. (2) Two methods of rats models were examine by feces traits and feces gastrointestinal through time testing has diarrhea, constipation feature, Can be used for IBS diarrhea, constipation-type animal model. (3) The number of PAR-2 positive cell in colon tissue of rats of the D-IBS group was notably larger than that in C-IBS and control group (P< 0.05), the result reveals that the change of PAR-2 is related to the occurrence of different IBS subgroups.