ABSTRACT
Objective To observe the effects of hyperbaric oxygen (HBO) on the apoptosis expression of intestinal mucosa during the different periods of ischemia-reperfusion injury in order to elucidate the underlying mechanisms. Method Rats were subjected to ischemia for 60 min by clamping superior mesenteric artery, and then had reperfusion for 60 min by unclamping. Rats were randomly divided into four groups: ischemia-reperfusion group (I/R), pre-emptive HBO or HBO treatment before ischemia (HBO-P) group, HBO treatment during ischemia period (HBO-I) group, and HBO treatment during reperfusion (HBO-R) group. After reperfusion for 60 min, samples of small intestine tissue were taken from the end portion of ileum for detecting the levels of ATP by using colorimetric method and the levels of caspase-3 by using immunochemistry. The levels of TNF-α in intestinal tissue were measured by using enzyme-linked immunosorbent assay method ( ELISA). All values were expressed in Mean ± Standard Deviation (x ± s). The different groups were compared among them with SNK- q test of OneWay analysis of variance (One-Way ANOVA plus SNK). Results The levels of TNF-α in HBO-I group were significantly lower than that in HBO-P group ( P ＜ 0.05), and significantly lower in HBO-P group than those in HBO-R or I/R groups ( P ＜ 0.05), and there was no significant difference in TNF-α between HBO-R and I/R group ( P ＞ 0.05). The levels of caspase-3 were significantly lower in HBO-I group than those in HBO-P group ( P ＜ 0. 05), and also significantly lower in HBO-P group than those in I/R or HBO-R groups ( P ＜ O. 05), and no significant difference caspase-3 was found between HBO-R and I/R groups. The ATP levels were significantly lower in HBO-I group than those in HBO- P group ( P ＜ 0. 05), and also significantly lower in HBO- P group than those in I/R or HBO-R group ( P ＜ 0.05), and no significant difference in ATP level between in HBO-R and I/R group. Conclusions There was a connection between HBO and small intestinal I/R injury as well as mucosal cell apoptosis. And HBO maintained ATP and aerobic metabolism, and inhibited the genesis of TNF-α, and thus in turn prevented intestinal mucosa cell from apoptosis. The best result was obtained when HBO was administered during ischemia period, and there was no effect found when HBO was employed during reperfusion period.