The role of cell adhesion molecules of inflammatory cell & brain endothe-lial cell in post brain ischemic/hypoxic hypoperfusion

在心脏骤停、休克、脑外伤和脑梗死等情况下，再灌注/再氧后脑灌注不足是一个严重的问题。我们研究了麻醉时多形核白细胞（PMNL）和脑内皮细胞黏附分子（CADM）对再氧后脑灌注不足的影响。在体外实验中，我们研究了氯胺酮和硫喷妥钠对未刺激、fMLP和pma刺激的人PMNLs细胞粘附分子表达的影响。从本实验中我们发现，临床浓度的硫喷妥钠可以减弱PMNLs上CD11b的增加，但不能减弱CD62L的增加，硫喷妥钠有保护局灶性脑缺血的作用。体外实验难以确定吸入麻醉剂对CADM的影响。因此，我们研究了异氟醚（0.5 ~ 1.5 MAC）对大鼠缺氧(5% O_2, 10 min) -复氧（120 mm）后CADM表达的影响。在脑低灌注指标方面，我们初步采用颅窗法测量血管直径。然而，这种方法由于打开颅骨而激活了PMNLs。相反，我们用近红外光谱法来评估脑氧合。0.5 MAC异氟醚麻醉下，再氧120min总Hb （tHb）和HbO_2（氧合血红蛋白）明显降低，提示再氧后低灌注。0.5 mac复氧后CD11b升高，与tHb、HbO_2呈显著负相关。而tHb、HbO_2及CD11b的表达均无明显变化。酶免疫染色检测的1.5 mac、icam - 1在复氧后升高。然而，我们无法定量测量该CADM的表达。根据这些发现，我们认为异氟醚和硫喷妥钠等麻醉药至少在一定程度上是由于PMNLs细胞粘附分子表达的衰减而起到保护缺血或缺氧脑低灌注的作用。少

Post reperfusion/reoxygenation brain hypoperfusion is a serious problem in conditions such as cardiac arrest, shock, brain trauma and cerebral infarction. We investigated the influence of cell adhesion molecules (CADM) of polymorphonuclear leukocyte (PMNL) and brain endothelial cells on post reoxygenation brain hypoperfusion during anesthesia. In vitro experiments, we investigated the effects of ketamine and thiopental on the expression of cell adhesion molecules of human unstimulated, fMLP- and PMA-stimulated PMNLs. From this experiment we found clinical concentration of thiopental, which has been reported to protect focal brain ischemia, attenuated the increase of CD11b on PMNLs, but not that of CD62L.In vitro experiment it is difficult to the effect of inhalation anesthetics on the CADM.Therefore, we investigated the influence of isoflurane (0.5 - 1.5 MAC) on the CADM expression after hypoxia (5% O_2, 10 min) -reoxygenation (120 mm) in rat. As to the indices of cerebral hypoperfusio … More n, we initially used cranial window method to measure the diameter of blood vessels. However, this method activated the PMNLs due to opening the cranium. Instead, we evaluated brain oxygenation by near infrared spectroscopy non-envasively. Under 0.5 MAC isoflurane anesthesia total Hb (tHb) and HbO_2 (oxy-hemoglobin) significantly decreased at 120 min after reoxygenation, suggesting that post-reoxygenation hypoperfusion occurred. The CD11b increased after reoxygenation at 0.5 MAC.There were significant negative relationshios between CD11b and tHb, and CD11b and HbO_2. In contrast, there was no change in tHb, HbO_2, and the expression of CD11b at. The 1.5 MAC.The ICAM-ldetected by enzyme immuno-staining increased after reoxygenation. However, we could not measure the expression of this CADM quantitatively. From these findings we suggested that anesthetics such as isoflurane and thiopental protected post ischemic or hypoxic brain hypoperfusion at least in part due to attenuation of the expression of cell adhesion molecules of PMNLs. Less