创伤失血后微循环多形核白细胞行为的性别差异

The effect of gender to microcirculatory polymorphonuclear leukocyte behavior after traumahemorrhage

目的 在体实时观察创伤失血性休克复苏后微循环多形核白细胞在毛细血管后微静脉内皮的附壁是否存在性别差异。并测定多形核白细胞黏附因子CD11b的表达。方法 实验动物为发情前期的雌性和成年雄性SD大鼠30只，分为雄性、雌性和对照3组，每组10只，其中对照组雌雄各5只。麻醉后通过放血的方法将平均动脉压降至（35±5）mmHg。并维持60min，然后在60min内用4倍于最大失血量的乳酸林格氏液进行复苏。对照组不进行休克及液体复苏。复苏后2h和6h在腹部正中作4cm切口，取出回盲部附近的肠系膜。显微镜下观察多形核白细胞在肠系膜毛细血管后小静脉内的附壁情况并录像。通过股动脉抽取外周血分离多形核白细胞，用流式细胞仪测定黏附分子CD11b的表达。复苏后6h将动物处死，测定肺组织髓过氧化物酶活性。结果 ①活体微循环观测：复苏后2h，雄性组大鼠毛细血管后小静脉内多形核白细胞数量明显增多，形成附壁。复苏后6h，雄性组毛细血管后小静脉内血流出现时快时慢甚至逆流的现象，说明雄性大鼠创伤失血性休克后微循环出现紊乱。②多形核白细胞附壁的分析：复苏后2h，雌性组（1．8±0．3）和对照组（0．4±0．2）的多形核白细胞附壁数明显低于雄性组（4．2±0．9，P〈0．05）。但6h后各组之间无明显变化。③多形核白细胞黏附分子CD11b表达的测定：复苏后2h和6h．多形核白细胞黏附分子CD11b的表达雄性组明显高于雌性组和对照组（P〈0．01），而雌性组和对照组间无明显差异。④肺组织髓过氧化物酶活性测定：休克复苏后6h，雄性及雌性肺组织髓过氧化物酶活性都与各自的对照组相比有显著的升高（P〈0．05），但雌性组升高明显低于雄性组（P〈0．05）。结论 创伤失血性休克后雌性大鼠多形核白细胞黏附分子CD11b的表达和多形核白细胞在毛细血管后微静脉内皮的附壁数量与雄性相比明显降低，多形核白细胞在肺组织中的浸润明显减少。

Objective To determine whether the behavior of polymorphonuclear （PMN） leukocyte adhesion to the endothelial cell after trauma-hemorrhage and resuscitation is different between genders by means of intravital microscopy. The expression of PMN adhesion molecule CDllb and the myeloperoxidase（MPO） activity of lung tissue were determined too. Methods Totally 30 proestrus female and adult male Sprague＇Dawley rats were divided into 3 groups： Female, Male and Contrast with 10 rats in each group. After anaesthesia the rats were bled to a mean arterial pressure （MAP） of （35±5） mm Hg for 60 rain, and then the animals were resuscitated with 4 times the volume of withdrawn blood with Ringer＇s lactate over 60 rain. The contrast group underwent no shock and no treatment. 2 h and 6 h after hemorrhagic shock and resuscitation a 4-cm midline laparotomy was made and the mesentery near to the ileum was exteriorized and the microcirculation blood flow as well as PMN-endothelial cell interaction was evaluated by means of intravital microscopy. The number of leukocytes sticking to the venular endothelium was determined .The expression of PMN adhesion molecule CD11b was determined by flow cytometry. 6 h after resuscitation, the lung tissues were analyzed for MPO activity. Results （1）Vital microcirculation observation： 2 h after resuscitation, the number of PMN in postcapiUary venules was more in male rats than female and contrast rats.6 h after resuscitation, the blood flow of postcapillary venules in male rats appear disorder, and this phenomena was not seen in female and contrast rats. （2）Analysis of PMN adherence：2 h after treatment, Female （1.8±0.3）, and Contrast （0.4±0.2） groups presented significant reductions in leukocyte adherence （cells/100 μm venule length）, compared with Male group （4.2±0.9, P〈0.05）. No differences were observed 6 h after treatment on leukocyte adherence. （3）Expression of PMN adhesion molecule CD1 lb：The expression of CD11b on PMN was significantly higher in Male animals compared with the Female and Contrast groups （P〈0.01）. （4）MPO activity of lung tissue： A significant MPO activity in lung tissues of both male and female rats was induced following trauma-hemorrhage, however, MPO activity levels were higher in males（P〈0.05）.Conclusion The PMN-endothelial cell interactions and PMN CD11b expression were down regulated in female rats after hemorrhagic shock and resuscitation. PMN sequestration in female lungs was lower than that of male lungs.