The role of androgen on brain protection by inhalation anestheticsduring cerebral reperfusion

围手术期脑缺血的诊断是困难的，但脑梗死的发作是致命的。因此，预防此类事件对麻醉管理非常重要。脑梗死的发病率存在性别差异，女性脑梗死的发病率普遍低于男性。这表明雌激素在这一机制中起着重要作用。另一方面，关于雄激素在缺血性事件中的作用的信息很少。据报道，通过吸入麻醉剂诱导的预适应的神经保护作用仅在男性中发现，而在女性中未见。性别差异可能与吸入麻醉剂对脑缺血的保护作用有关。然后我们打算研究雄激素和七氟醚在脑保护作用方面的相互作用。首先，为了评估缺血再灌注后的脑内皮功能，我们在Sprague-Dawley大鼠的大脑中动脉闭塞模型中使用了封闭颅窗制备。为了评价脑缺血再灌注前后的脑血管内皮功能，可以采用局部给药乙酰胆碱。遗憾的是，吸入七氟醚并没有观察到缺血再灌注引起的血管内皮功能障碍的衰减作用。此外，我们评估了主动脉交叉夹持和解除夹持后脊髓组织氧分压（PsptO2）。在麻醉家兔中，我们准备用组织PO2监测主动脉交叉夹持后PsptO2的测量。实验中，我们将18只动物分为3组，(d)对照组；N =6,(e)雌激素（17β雌二醇：20μg）组；N =6,(f)氟维司汀预处理（1mg/kg）组N =6。17β雌二醇可改善主动脉交叉夹持后20分钟和主动脉解夹后0、2、5分钟PsptO2值的恶化。氟维司汀预处理降低了这种改善。少

The diagnosis of perioperative cerebral ischemia is difficult, but the onset of cerebral infarction is fatal. Thus, the prevention of such event is very important for anestheticmanagement. Gender differences are observed in the incidence of cerebral infarction, and generally the incidence of cerebral infarction is less in females than males. It is suggested that the estrogen is strongly involved in this mechanism. On the other hand, there is little information about the role of androgen regarding ischemic events. It hasbeen reported that neuroprotective effect through preconditioning induced by inhalation anesthetic was found only in males, and not seen in females. There is a possibility that the gender difference is involved in the protective effect of inhaled anesthetic for the brain ischemia. Then we intended to investigate the interaction between androgen and sevoflurane regarding cerebral protective effect. Firstly, in order to evaluate thecerebral endothelial function following i … More schemia/reperfusion, we used the closed cranial window preparation associated with the middle cerebral artery occlusion model in the Sprague-Dawley rat. To evaluate the cerebrovascular endothelial function before and after cerebral ischemia/reperfusion, topical administration of acetylcholine could be applied.Unfortunately, by the inhalation of sevoflurane, the attenuation effect of vascular endothelial dysfunction caused by ischemia/reperfusion was not observed.Additionally, we evaluated the tissue oxygen partial pressure of spinal cord (PsptO2) following aortic cross-clamping and -unclamping. In anesthetized rabbits, we prepared for measurement of PsptO2 following aortic cross-clamping using tissue PO2 monitoring. In the experiment, we allocated 18 animals into 3 groups,(d) control group; n=6,(e) estrogen (17β estradiol: 20μg) group; n=6,(f) fulvestrant pretreatment (1mg/kg) groupn=6. Administration of 17β estradiol improved deterioration of the values in PsptO2 at 20 min after aortic cross-clamping and 0, 2, 5 min after aortic unclamp. The improvement was diminished by pretreatment of fulvestrant. Less