不同性别大鼠创伤失血性休克后多形核白细胞反应的差异及胃复安干预的实验研究

Experimental research of gender dimorphism in poly-morphonuclear cell response and metoclopramide intervention following trauma-hemorrhagic shock

本研究在以下几个方面具有创新：（1）将腺苷引入心肺复苏治疗中，观察腺苷与肾上腺素合用对心跳停搏后A主循环恢复率和复苏成功率的影响，结果表明合用腺苷可明显提高自主循环恢复率和复苏成功率；（2）观察腺苷在心肺复苏中对兔心、脑组织病理结构和超微结构的影响，结果表明腺苷可以明显减轻心脑组织的损害；（3）观察腺苷窒息大鼠心脏和肠系膜微循环的影响，并观察到肾上腺素对微循环无明显改善作用，联合应用腺苷可以改善微循环；（4）将激光多普勒血流量图象仪引入心肺复苏中，动态观察窒息大鼠肠壁组织血液灌流量变化，并观察到腺苷可以增加肠壁组织血流灌注量。

Objective （1）Determine the gender dimorphism of circulating PMN＇s response to T-H and resuscitation.（2）Determine whether the PMN＇s behavior of adhesion to the endothelial cell after traumahemorrhage and resuscitation is different between genders by means of intravital microscopy. The expression of cell adhesion molecule CD1 lb of PMN was determined too.（3）Determine whether administration of metoclopramide （MCP） produces any beneficial effects on the depressed immune function and the delayed apoptosis of PMN after severe hemorrhage.Methods （1）Proestrus female and adult male Sprague-Dawley rats （275-325 g） were divided into 3 groups： Female, Male and Contrast. A 5-cm midline laparotomy was made and then the wound were closed in layers. After that the rats were bled to a mean arterial pressure of （35＋5） mmHg for 1 h, and then the animals were resuscitated with 4 times the volume of withdrawn blood with Ringer＇s lactate over 1 h. The contrast group underwent no shock and treatment. 2 h and 24 h after resuscitation circulating PMN were assessed for superoxide and elastase production and tissues were analyzed for myeloperoxidase activity and Malondialdehyde. （2）2 h and 6 h after T-H shock and resuscitation the mesentery near to the ileum was exteriorized and the number of leukocytes sticking to the venular endothelium was determined. The expression of cell adhesion molecule CD1 lb of PMN was determined by flow cytometry. （3） After hemorrhagic shock and adequately resuscitated male Sprague-Dawley rats （275-325 g） were randomized into 2 groups： Metoclopramide（100 mg/100 g body weight） group, Saline vehicle group; the contrast group underwent no shock and treatment. 2 h later, the animals were killed and spleen tissue was homogenated used to determine IL-1β and IL-6. Plasma TNF-α and IL-8 levels were also measured. The expression of PMN Fas was measured too by flow cytometry. Results （1） At 2 and 24 h after resuscitation, PMA stimulated O2^- production was not influenced by T-H or gender. In contrast, fMLP-stimulated O2- and LPS-stimulated elastase release by PMNs from male T-H rats were greater than that of female rats. A significant MPO activity and MDA in tissues of both male and female rats were induced; however, MPO activity and MDA levels were higher in males following T-H. （2）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. The expression of CD1 lb on PMN was significantly higher in Male animals compared with the Female and Contrast groups （P〈 0.01）. （3）Release of IL-1β and IL-6 by spleen tissue from metoclopramide treated group was maintained after T-H, whereas release of IL-1β and IL-6 by spleen tissue from saline treated group rat was depressed by approximately 55%. In contrast, trauma-hemorrhage resulted in a threefold increase of plasma lever of TNF-α and IL-8 in saline treated group and plasma concentrations of TNF-α and IL-8 were unchanged in metoclopramide treated rat under such conditions. The Fas expression of PMN was depressed in saline treated group （P〈0.01） than the Contrast group, although the Fas expression of PMN was also depressed in metoclopramide treated rats （P 〈0.05）, but it was also higher than that of saline treated group. Condusions （1）Decreased PMN priming and activation in proestrus females, compared to males, occurs following T-H resulting in decreased cellular injury and organ damage that is likely to contribute to improved outcome under those conditions. （2）The PMN-endothelial cell interactions and PMN CD1 lb expression were down regulated in female rats after T-H shock and resuscitation. （3）The immunosuppression after hemorrhage may be restored by the use of single dose metoclopramide. Furthermore,metoclopramide may be a useful adjuvant in the treatment of the T-H shock-induced immunosuppression.