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、脑创伤和脑梗塞等情况下，再灌注/复氧后脑低灌流是一个严重的问题。本实验研究了麻醉状态下多形核白细胞(PMNL)和脑内皮细胞的细胞黏附分子(CADM)对复氧后脑低灌注的影响。在体外实验中，我们研究了氯胺酮和硫喷妥钠对人未刺激、fMLP和PMA刺激的PMNL细胞黏附分子表达的影响。本实验发现临床浓度的硫喷妥钠对大鼠局灶性脑缺血有保护作用，但对CD11b的升高无明显影响。在体外实验中，吸入麻醉剂对CADM的影响较大。因此，我们观察了异氟醚(0.5-1.5MAC)对大鼠缺氧(5%O2，10min)-复氧(120 MM)后CADM表达的影响。关于脑低血流…的指标此外，我们还初步采用了颅窗法测量血管内径。然而，这种方法由于打开了头盖骨而激活了PMNLS。相反，我们通过近红外光谱非环境地评估了大脑的氧合作用。在0.5MAC异氟醚麻醉下，复氧后120min总Hb(THb)和HBO_2(氧合血红蛋白)显著降低，提示复氧后出现低灌流。CD11b与THb、CD11b与HBO_2呈显著负相关，而THb、HBO_2、CD11b与CD11b的表达无明显变化。酶免疫染色检测ICAM-1在复氧后升高。然而，我们不能定量地测量这种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剂对脑缺血或缺氧后的低灌流具有保护作用，至少部分原因是由于PMNLS细胞黏附分子的表达减弱。较少

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