Abstract: Objective To observe the effect of blood purification on the expressions of ZO-1 (zonula occludens-1) and Occludin in intestinal tissue of small pigs with severe heatstroke.  Methods  A model of severe heatstroke in small pigs was constructed, and the intestinaql function was evaluated before and after blood purification intervention. According to the random number table method, the animals were divided into three groups: control group (n=6), blank control treatment was performed; model group (n=6), a model of heatstroke was established; intervention group (n=6), treated with blood purification. Pathological changes of intestinal tissue were observed using H-E staining. Chiu's score was used to assess the damage of intestinal tissue. Immunohistochemistry was used to observe the expressions of ZO-1 and Occludin in intestinal tissue.  Results  Reduced congestion and edema and relatively complete mucosa structure were found in intervention group, as compared with those in model group. Chiu's score was statistically different among the 3 groups (F=44.245, P<0.001). The expression levels of ZO-1 and Occludin were also statistically different among the 3 groups (ZO-1: F=152.477, P<0.001; Occludin: F=40.360, P<0.001).  Conclusion  Blood purification can be protective against intestinal injury due to heatstroke in small pigs, probably relating to the upregulation of ZO-1 and Occludin expressions.

Key words: Heatstroke, Intestinal tissue, Tight junction protein, Blood purification