目的    研究不同缺血时间下小肠组织细胞凋亡程度与GRP78表达量之间的关系。 方法    选用4周龄雌性SD大鼠，随机分为对照组，损伤组（缺血20、40、60、80和100 min），于再灌注6 h后处死，检测血清中DAO的表达水平，取小肠组织检测细胞凋亡情况以及GRP78表达情况，并观察大鼠两周内的存活情况。  结果    与对照组相比，损伤组GRP78的表达量随着缺血时间的延长逐渐升高，在80 min时达到峰值；与损伤组缺血80 min时相比，在100 min时GRP78 mRNA表达水平显著下降；与损伤组缺血80 min时相比，在100 min时GRP78蛋白表达水平略有下降；与对照组相比损伤组随着缺血时间的增加，细胞凋亡程度逐渐增加；与对照组相比，缺血时间越长大鼠的两周存活率越低。  结论    随着缺血时间的延长，大鼠小肠组织细胞绒毛层及粘膜层的细胞凋亡程度逐渐增加；在80 min之前随着大鼠小肠缺血时间的延长，GRP78表达水平逐渐升高，100 min时虽然小肠组织损伤程度较80 min时增大，但GRP78表达水平较80 min时降低，GRP78的表达水平与不同缺血时间小肠组织细胞凋亡程度密切相关。

 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.