Effect Of Reconstructive AFGF On Intestinal Epithelial Cell Apoptosis And Epithelial Barrier Function After Ischemia And Reperfusion

AIM: To investigate the effect of reconstructive acidic fibroblast growth factor (raFGF) on the expression characteristics of apoptosis-related genes, p53, p21, bax and bcl-2 in rat small intestine after ischemia-reperfusion (I/R) insult underlying the protective mechanism of extrogenous aFGF on gut ischemia /reperfusion injury.METHODS: One hundred and forty-four Wistar rats were divided randomly into four groups, namely intestinal ischemia-reperfusion group (R), intestinal ischemia group (I), reconstructive aFGF treatment group (A) and sham-operated control group (C). In group I, the animals were killed after 45 minutes of superior mesenteric artery (SMA) occlusion, while in group R and A, the rats sustained 45 minutes of SMA occlusion and were treated with normal saline(0.15ml) and reconstructice aFGF (20g/kg), then sustained 15min, 30min, 1, 2, 6, 12, 24 or 48hr of reperfusion respectively. In sham-operated control group, SMA was separated, but without occlusion. The levels of plasma D-lactate were determined. Apoptosis in intestinal villus was determined with terminal deoxynucleotidy transferase mediated dUTP-biotin nick-end labeling technique (TUNEL). Intestinal tissue samples were taken not only for RT-PCR to detect bax, bcl-2, p53 and p21 gene expression, but also for immunohistochemical analysis of detection Bax, Bcl-2, P53 and P21 protein expression and distribution. RESULTS: The rat survival rates in aFGF treated group were higher than intestinal I/R control group (P0.05) and in plasma, the D-lactate levels were markedly lower than that of intestinal R group (P<0.05). The improvement of intestinal histological structures and lower apoptotic rates were observed at 2h 6h and 12h after the reperfusion in aFGF treated group compared with R group. The gene expressions and protein contents of Bax, P53 and P21 were significantly decreased in A group versus R group, while mRNA and protein contents of Bcl-2 in A group were obviously higher than those in R group. CONCLUSION: The changes in histological structure and the increment of apoptotic rate indicatedthat the intestinal barrier was damaged after intestinal I/R injury, whilst extrogenous acidic flbroblast growth factor (aFGF) could alleviate apoptosis induced by ischemia and reperfusion in rat intestinal tissues, in which apoptosis-induced genes p53, p21 and bax and apoptosis-inhibited gene bcl-2 might play important roles.