The effects of apoptosis and proliferation on the pathogenesis of rat stress ulcer / 中华消化杂志

ABSTRACT

Objective To investigate the gastric epithelial cell death and proliferation in water restraint stress (WRS) rats during the processes of pathogenesis of stress ulcer, by means of biochemical and morphological analysis. Methods Apoptotic cells were quantitated in gastric mucosa before or at different time points after WRS by TUNEL techniques, and the morphological changes of cells were observed by transmisson electronic microscope whilst the cell proliferation was detected by immunohistochemical staining for proliferating cell nuclear antigen (PCNA). Results The result revealed that in normal controls, the apoptotic cells were seen only occasionally at the surface epithelium,and the PCNA positive cells were found in the proliferative zone of the gastric glands. In contrast, the apoptotic quantities rose significantly from 2 h after the WRS to 5 h after the termination of WRS, and reached a peak gradually,while PCNA positive cells decreased significantly. At 8～12 h after the WRS ,the apoptotic cells gradually declined but failed to return to normal even at 24 h. The PCNA cells increased to reach a peak and declined at 24 h towards the value observed in the intact rats. Under the transmission electronic microscopy it showed that in contrast to normal mucosal cells, the morphology of apoptotic cells changed with various characteristics. Conclusions The results suggested that the epithelial apoptosis significantly increased, whereas proliferation decreased; the imbalance between both them induced the damage of gastric mucosal integrity. During the initial stage of mucosal recovery from stress lesion, the apoptosis appears to activate the mucosal cell proliferating, a response leading to the recovery of the mucosa from the stress damage.