水通道蛋白1在急性坏死性胰腺炎大鼠胰腺组织的表达及其意义

目的 探讨水通道蛋白1(AQP1)在急性坏死性胰腺炎(ANP)大鼠胰腺的表达及其意义.方法 将48只雄性SD大鼠随机分为对照组和ANP组,制模后3、6、12、18 h各时间点分别处死6只.记录腹水量,测定血清淀粉酶;采用酶联免疫吸附试验(ELISA)检测血清AQP1含量;苏木素-伊红(HE)染色观察胰腺组织病理改变;伊文思兰染料(EB)血管外渗法检测胰腺组织毛细血管通透性;免疫组织化学和Westem blot法检测胰腺组织AQP1蛋白表达;荧光定量聚合酶链反应(PCR)检测AQP1基因mRNA表达.结果 (1)对照组3、6、12、18 h血清淀粉酶水平分别为(1308±759)、(1077±508)、(1325±761)、(1328±762)U/L,ANP组分别为(9102±2199)、(8799±1634)、(9398±1473)、(9484±862)U/L;对照组胰腺组织EB含量分别为(205.61±32.99)、(141.46±27.18)、(96.94±26.79)、(61.43±24.82)mg/L;ANP组分别为(273.59±23.47)、(253.51±31.68)、(221.15±73.68)、(185.28±42.35)mg/L;血清AQP1含量对照组为(74.08±11.80)、(78.49±9.06)、(75.77±7.37)、(72.75±13.87)mg/L,ANP组为(73.29±9.61)、(62.85±7.28)、(62.07±4.39)、(46.33±11.91)mg/L,两组比较差异均有统计学意义(P<0.01).(2)对照组3、6、12、18 h免疫组织化学灰度值分别为114.13±7.92、122.39±7.99、145.98±6.48、113.98±6.48,ANP组分别为80.07±14.89、110.54±4.45、103.77±10.48、99.18±6.95;对照组Western blot蛋白含量分别为1.19±0.33、1.02±0.25、0.90±0.33、1.06±0.20,ANP组分别为0.83±0.11、0.96±0.21、0.58±0.28、0.72±0.14.结果 均显示ANP组胰腺AQP1蛋白表达低于对照组(P<0.05);(3)对照组3、6、12、18 h荧光定量PCR检测ANP组胰腺AQP1基因mR-NA表达分别为2.13±0.63、2.02±1.40、2.07±0.86、2.49±2.47,ANP组为0.91±0.22、1.01±0.83、0.48±0.23、0.61±0.51,ANP组较对照组减弱(P<0.01).结论 ANP大鼠胰腺组织AQP1表达明显减弱,这可能在毛细血管渗漏综合征的发生中起重要作用.

Expression and significance of aquaporin 1 in pancreatic tissue of rats with experimental acute necrotizing pancreatitis

Objective To study the expression of aquaporin 1 ( AQP1 ) in pancreas and its pathogenic role in rats with experimental acute necrotizing pancreatitis (ANP). Methods Forty-eight male Sprague-Dawley rats were randomly divided into two groups : control group ( n = 24 ) and ANP group ( n = 24). Six rats in each group were sacrificed at 3,6,12 and 18 h after induction of experimental models. Quantity of ascites and levels of serum amylases were measured at each time point. Serum AQPI was determined by ELISA. Pathological changes of pancreatic tissues were examined. Capillary permeability in pancreatic tissues was tested by Evans Blue (EB) extravasation method. AQPI expression in pancreatic tissues was detected by immunohistochemieal staining, Western blot and fluorescence quantitative polymerase chain reaction (FQ-PCR). Results (1) Serum amylase level at 3,6,12, and 18 h in control group was (1308±759) ,(1077±508), (1325±761),(1328±762) U/L,and that in ANP group was (9102± 2199), (8799±1634), (9398±1473), (9484±862) U/L respectively. The concentration of EB in pancreatic tissues at each time point in control group was (205.61±32.99), (141.46±27.18 ), (96.94± 26.79), (61.43±24.82) mg/L, and that in ANP group was ( 273.59±23.47 ), ( 253.51±31.68 ), (221.15±73.68 ), (185.28±42.35) ,respectively. There was significandy difference between two groups. Serum AQP1 level in control group at each point was ( 74.08±11.80), (78.49±9.06 ), (75.77± 7.37 ), ( 72.75±13.87 ) mg/L, and that in AN P group was (73.29±9.61 ), ( 62.85±7.28 ), (62.07± 4.39 ), (46.33±11.91 ) mg/L, respectively ( P < 0.01 ). ( 2 ) Protein expression of AQPI in pancreatic tissues detected by immunohistochemical staining in control group at each time point was 114.13±7.92, 122.39±7.99,145.98±6.48,113.98±6.48, and that in ANP group was 80.07±14.89,110.54± 4.45,103.77±10.48,99.18±6.95;Protein expression of AQP1 in pancreatic tissues detected by Western blot in control group at each time point was 1.19±0.33,1.02±0.25,0.90±0.33,1.06±0.20,and that in ANP group was 0.83±0.11,0.96±0.21,0. 58±0.28,0.72±0.14, respectively ( P < 0.05 ). ( 3 ) The mRNA level of AQP1 gene expressed in pancreas in control group at each time point was 0.91±0.22,1.01±0.83,0.48±0.23,0.61±0.51,and that in ANP group was 2.13±0.63,2.02±1.40, 2.07±0.86,2.49±2.47,respectively (P<0.01).Condusion The expression of AQP1 wasdown-reg-ulated in pancreas in rats with ANP,which might could play an important role in the pathogenesis of capil-lary leak syndrome.