大鼠心肺复苏后脑Occludin蛋白表达与血脑屏障及脑水肿的关系

摘要

Objective To explore the change of occludin protein expression after cardiopulmonary resuscitation(CPR) and its correlations with blood-brain barrier(BBB) and cerebral edema in rats.Methods Totally 200 male SD rats were randomly divided into group A(Sham group,n =100,treated with anesthesa,arteriovenous intubation and tracheal intubation) and group B(CPR group,n =100,sudden cardiac arrest and CPR model);group A was subdivided into group A1 and group A2,group B were subdivided into group B1 and group B2,with respectively 50 rates in each subgroup.Group A1,B1 were used for testing occludin protein expression and cerebral water conten;rats were executed 2,6,12,24,48 h after 10 min of postoperative stability(group A1) or restoration of spontaneous circulation(ROSC) (group B1).Occludin protein expression was tested by immunohistochemical method;cerebral water content was tested by wet-dry weight method.Group A2,B2 were used for evaluating the permeability of BBB;rats were injected Evans blue(EB) immediately and 4,10,22,46 h after 10 min of postoperative stability (group A2) or ROSC (group B2),and they were executed 2 h after injection;cerebral EB content was tested.Results At 2,6,12,24,48 h after ROSC,occludin protein positive cell numbers and cerebral water contents in group B1 showed significant differences among each time point[Occludin protein positive cell numbers:(68.2 ± 1.0),(42.1 ± 1.6),(18.1 ± 1.1),(37.8 ±0.7),(61.2 ± 1.0),cerebral water contents:(77.4±0.7)％,(79.2±0.8)％,(80.2±0.7)％,(79.6±0.5)％,(77.2 ±1.2)％](P＜0.01),and there were significant differences between group A1 [Occludin protein positive cell numbers:(86.8 ± 1.3),(85.1±2.7),(84.9 ±2.8),(82.1 ±3.1),(83.8 ±2.5),cerebral water contents:(76.0 ±0.9)％,(75.9±0.9)％,(76.2±1.0)％,(75.9±0.9)％,(75.8±0.9)％] and groupB1(P＜0.05orP＜0.01);cerebral EB content in group B2 showed significant differences among each time point [(0.50 ± 0.04),(0.70 ± 0.02),(0.90 ±0.04),(0.87 ±0.03),(0.69 ±0.03)μg/g] (P ＜0.01),and there were significant differences between group A2 [(0.24 ± 0.01),(0.23 ± 0.01),(0.23 ± 0.01),(0.25 ± 0.01),(0.23 ± 0.04) μg/g] and group B2 (P ＜ 0.01).Cerebral occludin protein positive cell numbers was negatively correlated with EB content and water content (r =-0.862,-0.668;P ＜ 0.01);cerebral EB content was positively correlated with water content (r =0.672,P ＜ 0.01).Conclusions CPR leads to the decrease of cerebral occludin protein expression,the increase of BBB permeability and the formation of cerebral edema.Occludin protein expression is negatively correlated with BBB permeability and cerebral edema.%目的 探讨大鼠心搏骤停心肺复苏后脑Occludin蛋白表达的变化及其与血脑屏障和脑水肿的关系.方法 选取200只雄性SD大鼠,采用随机数字表法分为A组(对照组,100只,仅行麻醉、动静脉置管及气管插管)及B组(心肺复苏组,100只,制作心搏骤停与心肺复苏模型);A组再分为A1、A2组,B组再分为B1、B2组,各50只.A1组于术后稳定10 min后、B1组于自主循环恢复(ROSC)后2、6、12、24、48 h各处死10只大鼠取脑组织,用免疫组化方法检测脑组织中Occludin蛋白表达,用干湿重法测脑组织含水量.A2组于术后稳定10 min后、B2组于ROSC后即刻及4、10、22、46 h各取10只大鼠于经尾静脉注射伊文思兰来示踪血脑屏障,注射后2h处死大鼠取脑组织,测定脑组织中伊文氏蓝含量.结果 B1组ROSC后2、6、12、24、48 h,脑Occludin蛋白阳性细胞数、脑组织含水量各时点之间差异均有统计学意义[Occludin蛋白阳性细胞数:(68.2±1.0)、(42.1±1.6)、(18.1 ±1.1)、(37.8±0.7)、(61.2±1.0)个/高位视野,脑组织含水量:(77.4±0.7)％、(79.2±0.8)％、(80.2±0.7)％、(79.6±0.5)％、(77.2±1.2)％](P＜0.01),各时点与A1组[Occludin蛋白阳性细胞数:(86.8±1.3)、(85.1±2.7)、(84.9±2.8)、(82.1±3.1)、(83.8±2.5)个/高位视野,脑组织含水量:(76.0±0.9)％、(75.9±0.9)％、(76.2±1.0)％、(75.9±0.9)％、(75.8±0.9)％]比较差异均有统计学意义(P ＜0.05或P＜0.01);B2组脑组织伊文氏蓝含量各时点之间差异均有统计学意义[(0.50 ±0.04)、(0.70 ±0.02)、(0.90 ±0.04)、(0.87±0.03)、(0.69±0.03) μg/g] (P ＜0.01),各时点与A2组[(0.24±0.01)、(0.23 ±0.01)、(0.23±0.01)、(0.25±0.01)、(0.23 ±0.04) μg/g]比较差异均有统计学意义(P＜0.01).脑Occludin蛋白阳性细胞数与脑组织伊文氏蓝含量、脑组织含水量呈负相关(r=-0.862、-0.668,P＜0.01),脑组织伊文氏蓝含量与含水量呈正相关(r =0.672,P＜0.01).结论 大鼠心肺复苏后脑Occludin蛋白表达下降,血脑屏障通透性增加,脑水肿形成,ROSC后12 h最明显;脑Occludin蛋白表达与血脑屏障通透性及脑水肿程度呈负相关.