水通道蛋白1在急性坏死性胰腺炎大鼠肠壁血管内皮屏障功能障碍中的作用

Role of Aquaporin 1 on capillary endothelial barrier dysfunction of intestine in rat with experimental acute necrotizing pancreatitis

目的探讨水通道蛋白1（aquaporin 1，AQP1）对急性坏死性胰腺炎（acute necrotizing pancreatitis，ANP）大鼠肠道毛细血管内皮屏障功能障碍的影响。方法160只雄性Sprague—Dawley大鼠随机分为对照组、ANP组、生理盐水组、地塞米松组及乙酰唑胺组，制模后3、6、12、18h各时间点分别处死8只。记录腹水量，测定血清淀粉酶；HE染色观察肠壁组织病理改变；电镜观察肠壁组织超微结构；伊文思兰染料血管外渗法检测肠壁组织毛细血管通透性；荧光定量PCR检测肠壁组织AQP1 mRNA的表达；Western blot法检测肠壁组织AQP1蛋白表达。结果（1）ANP组血清淀粉酶水平显著高于对照组，地塞米松组低于ANP组，乙酰唑胺组高于ANP组（P〈0．05）；（2）ANP组肠壁组织伊文思兰含量明显高于对照组，地塞米松组低于ANP组，乙酰唑胺组高于ANP组（P〈0．05）；（3）ANP组肠壁组织AQP1 mRNA表达显著低于对照组，地塞米松组表达显著高于ANP组，乙酰唑胺组显著低于ANP组（P〈0．05）；（4）ANP组肠壁组织AQP1蛋白含量明显低于对照组，地塞米松组高于ANP组，乙酰唑胺组低于ANP组（P〈0．05）。结论AQP1在ANP大鼠肠壁组织毛细血管渗漏的发生中起重要作用，调控AQP1的表达对保护血管内皮屏障功能有重要意义。

Objective To study the effect of aquaporin 1 on intestinal capillary endothelial barrier in rats with experimental acute necrotizing pancreatitis （ANP）. Methods In this study, 160 male Sprague-Dawley rats were randomly divided into five groups： Control group （n = 32）, ANP group （n = 32）, NS group, Dexamethasone group, and Acetazolamide group. Eight rats in each group were sacrificed at 3, 6, 12 and 18 h after induction of experimental models. Volume of ascites and levels of serum amylases were determined at each time point. Pathological changes in intestine tissues were observed under electron microscope after HE staining. Capillary permeabilities in intestine tissues were detected by Evans blue （ EB ） extravasation experiment. The mRNA and protein expressions of AQP1 in intestine tissue were determined by real-time PCR and Western blotting, respectively. Results Serum amylase level in ANP group was significantly higher than that in control group. Amylase level in dexamethasone group was lower than that in ANP group, and amylase level in acetazolamide group was higher than that in ANP group at 12 h （P 〈 0. 05 ） ; The concentration of EB in intestine tissues at each time point in ANP group was significantly higher than those in control group, and EB in dexamethasone group was lower than those in ANP group at 6, 12 and 18 h. EB in acetazolamide group was higher than that in ANP group at 3 h （ P 〈 0.05 ） ; The mRNA expression of AQP1 in ANP group was significantly lower than that in control group. The expression of AQP1 in dexamethasone group was higher than those in ANP group at 6, 12 and 18 h, and the expression of AQP1 in acetazolamide group was lower than that in ANP group at 3, 6, 12 h in intestine tissue （P 〈 0. 05 ）. Protein expression of AQP1 in tissues in ANP group was significantly lower than that in control group. The expression of AQP1 in dexamethasone group increased more than that in ANP group at 3, 6, 12 h, and the expression of AQP1 in acetazolamide group was lower than that in ANP group at 3 h, 6 h （ P 〈 0. 05 ）.Conclusions The expression of AQP1 is down-regulated in intestine tissue in rats with acute necrotizing pancreatitis, and AQP1 could play an important role in the pathogenesis of capillary endothelial barrier dysfunction.