The Effect And Mechanism Of Levofloxacin And Bifidobacteria On Rat Visceral Sensation In Dextran Sodium Sulfate Induced Colitis With Low Grade Inflammation

Aims:High visceral sensation has been presumed to be one of the most important mechanisms in the development of irritable bowel syndrome (IBS). However, the effect of bowel micro-ecosystem unbalance on visceral sensation has still not been well demonstrated. In this study, dextran sodium sulfate induced rat colitis with low grade inflammation was used as a model to investigate the effect of levofloxacin and bifidobacteria on the alteration of visceral sensation and several inflammation related cytokines.Methods:48 male SD rats were randomly divided into control group (group D, 16 cases) and study group (32 cases). The rat colitis with low grade inflammation was induced by 1.5%DSS administration in study group, while the rats in control group were treated with distilled water. 8 rats were randomly executed in each group to count the score of inflammation in day 7. The rest rats in study group were divided into there sub-groups, including group A, B and C. Group A and B were treated with levofloxacin and bifidobacteria, respectively, while the rats in group C were treated with distilled water. The alterations of the therapeutic effect were assessed by the changes and significances of 5-hydroxytryptamine and serotonin reuptake transporter in the colon mucosa and discharge of external oblique muscle of abdomen and interleukin-6 in serum and water content in stool.Results:(1)water content in stool: Significant difference of the stool water content was found only between group C and D after treatment (p<0.05). Comparing with first results of water content, the second results in four groups there weren't significant differences (p>0.05)(2)patho-score: After drinking 1.5%DSS, Comparing with normal group, the patho-score of model group increased, there was significant difference (p>0.05). Significant difference of the patho-score was found only between group C and D after treatment (p<0.05).(3) discharge of external oblique muscle of abdomen: Comparing with the group of C, the width and the number of discharge of external oblique muscle of abdomen of post-treatment groups decreased , there were significant differences(p<0.05) (except the number of discharge in pressure of 60mmHg between group A andC). Comparing with the group of D, the width and the number of discharge of external oblique muscle of abdomen of post-treatment groups increased a little , but there weren't significant differences(p>0.05). Comparing with the first results, the width and the number of discharge of external oblique muscle of abdomen of post-treatment groups decreased, there were significant differences (p<0.05) in pressure of 60mmHg and 80mmHg. Comparing with the first results, the width and the number of discharge of external oblique muscle of abdomen of C and D groups didn't change much, there weren't significant differences(p>0.05).(4)IL-6: Significant difference of the density of IL-6 was found only between group C and D after treatment (p<0.05). Comparing with the results of first test, the density of IL-6 of second test of A and B groups decreased, there were significant differences(p<0.05), the density of IL-6 of second test of C and D groups changed a little , there weren't significant differences(p>0.05).(5)5-HT and SERT:Comparing with the group of C, the average gray scale of 5-HT and SERT of proximal colon and distal colon of A and B and D group changed much, there were significant differences (p<0.05).Comparing with the group of D, the average gray scale of 5-HT and SERT of proximal colon and distal colon of A and B group changed a little, there weren't significant differences (p>0.05).Conclusions:The rats with low grade inflammation have high visceral hyperalgesia, and levofloxacin and bifidobacteria can reduce visceral hyperalgesia and the levels of interleukin-6 in serum and the score of inflammation.