EXPRESSION OF NEURONAL NITRIC OXIDE SYNTHASE AND HEME OXYGENASE-2 IN COLON AFTER STRESS IN RATS / 解剖学报

ABSTRACT

Objective To investigate the expression of neuronal nitric oxide synthase(nNOS) and heme oxygenase-2(HO-2) in colon after stress in rats. Methods Water immersion-restraint stress(WRS) model was performed.The expressions of nNOS and HO-2 in colon of rats were examined by immunohistochemical staining and analysed by image analysis system. Results In control group rat,nNOS immune-positive substance mostly expressed in neurons of submucous plexus and myenteric plexus and HO-2 mostly expressed in lamina propria mucosal muscles of colon mucosa,circular muscles of colon and the endothelium and smooth muscle cells of submucosal bloodvessels.Compared with control group rat,the average gray value of nNOS positive neurons in submucous plexus and myenteric plexus and the average number of nNOS positive neurons increased significantly,the average gray value of HO-2 positive mucosal muscles and the positive unit(PU) of circular muscles increased in stress group rat,moreover,nNOS expression in mucosal epithelial cells and lamina propria lymphocytes and HO-2 expression in some large intestinal glands were observed.Compared with stress group rat,the average gray value of nNOS positive neurons in submucous plexus and myenteric plexus and the average number of nNOS positive neurons decreased in stress +L-NAME group,the average gray value of HO-2 positive mucosal muscles and the PU of circular muscles decreased in stress +ZnPP group.Conclusion Both nitric oxide(NO) and carbon monoxide(CO) are important gaseous signal molecules and neurotransmitters in colon of rats and may play a cooperative role in colonic functional disorder induced by WRS.