失血性休克猪肠黏膜水通道蛋白8表达的变化

Changes in expression of aquaporin-8 in intestinal mucosa in pigs with hemorrhagic shock

目的 评价失血性休克猪肠黏膜水通道蛋白8（AQP8）表达的变化.方法 健康成年巴马小型猪16头,雌雄不拘,体重22～ 25 kg,采用随机数字表法分为2组（n=8）：假手术组（S组）和失血性休克组（HS组）.术前禁食8h,静脉注射异丙酚3 mg/kg麻醉.S组麻醉后经股动脉和颈内静脉置管;HS组麻醉置管后,采用经15 min将40％的血容量匀速放出的方法制备猪失血性休克模型.于麻醉前（T0）、失血性休克30 min（T1）、1.0、1.5、2.0、3.0和4.0 h（T2-6）时采集颈内静脉血样,采用ELISA法检测血清D-乳酸和肠脂肪酸结合蛋白（I-FABP）的浓度;T6时采血后放血处死动物,取肠组织,观察病理学结果;采用干湿比法计算肠含水量,ELISA法检测肠黏膜AQP8的含量.结果 与S组比较,HS组T2.6时血清D-乳酸浓度、T1-6时血清I-FABP浓度、T6时肠含水量和AQP8含量升高（P＜0.05）.S组肠黏膜未见明显变化;HS组肠黏膜损伤严重,可见出血,炎性细胞浸润,上皮细胞坏死.结论 失血性休克猪肠损伤的机制与肠黏膜AQP8表达上调有关.

Objective To evaluate the changes in the expression of aquaporin-8 （AQP8） in intestinal mucosa in pigs with hemorrhagic shock.Methods Sixteen Bama miniature pigs,weighing 22-25 kg,were equally and randomly divided into sham operation group （group S） and hemorrhagic shock group （group HS）.The animals were fasted for 8 h before operation.The animals were anesthetized with propofol 3 mg/kg injected via the auricular vein,and tracheostomized and mechanically ventilated.In group S,the femoral artery and internal jugular vein were only cannulated.In group HS,the femoral artery and internal jugular vein were cannulated for blood pressure and mean arterial pressure monitoring and blood sampling.Hemorrhagic shock was then induced by removing 40 percent of blood volume over 15 min.Before anesthesia （T0）,and at 30 min and 1.0,1.5,2.0,3.0 and 4.0 h after the end of blood-letting （T1.6）,blood samples were collected for determination of serum D-lactate and intestinal fatty acid binding protein （I-FABP） concentrations.After blood sampling at T6,the pigs were sacrificed,and intestinal specimens were obtained for microscopic examination and for determination of AQP8 cotent in intestinal mucosa （by ELISA）.The water content of intestines was calculated by wet/dry weight ratio.Results Compared with group S,the serum D-lactate concentrations at T2-6,I-FABP concentrations at T1-6,and water content of intestines were significantly increased,and the cotent of AQP8 was up-regulated at T6 in group HS.No changes were found in the intestinal mucosa in group S.In group HS,severe damage to the intestinal mucosa was found,and bleeding,inflammatory cell infiltration,and epithelial cell necrosis were observed.Conclusion The mechanism of hemorrhagic shock-caused damage to intestines is related to up-regulated expression of AQP8 in intestinal mucosa in pigs.