ABSTRACT
Objective:To study the characteristics of intestinal tract pathological injury of rats in hypobaric hypoxia at different high altitude.Methods:30 male SD rats were randomly divided into 5 groups:Plain group (n=6),High-altitude (HA) 5000 m for 10 day group(n=6),HA 5000 m for 21day group(n=6),HA 6500 m for 10day group(n=6),HA 6500 m for 21day group (n=6).Rats were raised normally either in plain or simulated high altitude environment,at the corresponding time point,rats were euthanized,small intestines were harvested,fixed tissues were processed routinely into paraffin and sections were stained routinely with hematoxylin and eosin.Morphologic parameters were measured by optical microscope and then the pathological injury score were evaluated.Results:The pathological injury scores ofjejunnm and ileum in the high altitude group were significantly higher than that of the plain group (P＜0.01),the pathological injury scores of jejunum,ileum and colon were significantly higher in the HA 5000 m for 21 day group than that of the HA 5000 m for 10 day group,but significant lower than that of the HA 6500 m for 21 day group,the pathological injury scores of jejunum,ileum and colon were significantly higher in the HA 6500 m for 10 day group than that of the HA 5000 m for 10 day group(P＜0.01,P＜0.05).The pathological injury scores of colon were significantly higher in the groups of the high altitude than the plain group except for the HA 5000 m for 10 day group (P＜0.01,P＜0.05).The pathological injury scores of jejunum had significant different with that of the colon in the HA 5000 m for 21 day group (P＜0.05);the pathological injury scores of both jejunum and ileum had significant different with that of the colon in the HA 6500 m for 21 day group(P＜0.05,P＜0.01).Conclusions:The injuries of the intestinal mucosa became serious with the with rising altitude and the stayed time,the intestinal injuries were more serious than that of colon at same situation,however there were no significant different between jejunum and ileum,the injuries of colon happened later than intestine,and they correlated with the stay time in the high altitude,which indicated that intestinal injury should be pay more attention in the early time of entering the hypobaric hypoxia environment of the high altitude.