PAR-2-Mediated Relaxation of Rectum is Impaired Following Bacillary Dysentery in Rat - Special Issue

Background: PAR-2 activation modifies the intestinal motility and takes part in gastrointestinal motility disturbances under intestinal infection or inflammation, but its role in the regulation of normal rectum motility and its change following bacillary dysentery remains unclear. Methods: Healthy male wistar rats, weighing 200?220 g were paired according to the weight and then divided randomly into control and Shigella flexneri-treated groups. Shigella flexneri was administrated intragastrically in healthy male rats to induce bacillary dysentery. The effect of PAR-2 activation on the normal rectal motility was detected using tension recording system. The change of PAR-2-mediated effect was investigated at different time following the infection. Results: The activation of PAR-2 induced a dose-dependent relaxation on the rectal longitudinal strips. This effect was TTX insensitive. After the infection with Shigella flexneri, the inhibitory effect induced by PAR-2 activation was impaired at day 11 and 18, then recovered to control level at day 25 and 35, besides, the basal mechanical activity of the rectal strips increased at day 11 following infection and recovered to control level at day 18, 25 and 35. Conclusions: These data indicated that PAR-2 activation regulated the rectal motility and this effect was impaired following bacillary dysentery.