Abstract:  Objective    To study the relationship between the degree of apoptosis of small intestinal tissue cells and the expression of GRP78 under different ischemic times.    Methods    Four-week-old female SD rats were randomly divided into a control group and injury groups (20, 40, 60, 80, and 100 minutes of ischemia). They were sacrificed 6 hours after reperfusion. The expression level of DAO in the serum was detected. Small intestine tissue was used to detect cell apoptosis and GRP78 expression, and the survival of rats within one week was observed.    Results    Compared with the control group, with the increasing of ischemia time, the expression of GRP78 in the injury group gradually increased, reached a peak at 80 min. Compared with the injury group at 80 min of ischemia, the expression level of GRP78 mRNA at 100 min decreased significantly. Compared with the injury group at 80 min of ischemia, the GRP78 protein expression level decreased slightly at 100 min. Compared with the control group, with the increasing of ischemia time, the degree of apoptosis in the injury group gradually increased.  Compared with the control group, the longer the ischemic time, the lower the two-week survival rate of the rats.    Conclusions    With the increasing of ischemia time, the degree of apoptosis of rat small intestinal tissue cells in the villous layer and mucosal layer gradually increased. Before 80 min, with the prolongation of rat small intestine ischemia time, the expression level of GRP78 gradually increased. Although the injury degree of small intestine tissue increased at 100 min compared with that at 80 min,  the expression level of GRP78 decreased than that at 80 min. The expression level of GRP78 was closely related to the degree of apoptosis of small intestine tissue cells at different ischemic times.

Key words: Small intestine ischemia reperfusion injury,  ,  , GRP78,  ,  , Cell apoptosis