MECHANISMS OF PERINATAL CEREBRAL BLOOD FLOW REGULATION

这些研究的目标是继续在新生羔羊的工作 后窒息模型，以寻求了解的机制， 围产期脑损伤 其中一组研究旨在检查 脑循环到低碳酸血症在“强调”新生羔羊。 利用放射性标记的微球方法和矢状面 窦导管采集脑静脉引流液、脑血 流量、O2输送、O2消耗和部分O2提取 将被测量或计算。 第一项研究将 检查脑循环对低碳酸血症的反应， 窒息后的新生羔羊，而第二组将检查 同样的问题在一个新开发的新生羔羊肺 高血压模型 过度换气在临床上应用最多 经常发生在窒息的肺动脉高压婴儿中。 这些研究将大大有助于评估 新生儿过度通气治疗 其他3项研究将考虑脑损伤的机制， 窒息 核心假设是大部分脑损伤 与窒息相关的症状发生在事件之后而不是事件发生期间。 这些研究将利用新生羔羊窒息后模型。 其中一组研究将评估后的发展差异， 窒息线粒体功能。 第二项研究将评估 窒息的神经生理和病理后果， 第三组研究将评估窒息前 葡萄糖浓度对神经生理和病理后遗症的影响 以及窒息后线粒体功能的影响。 一个 许多研究的基本主题将是 氧自由基在窒息后神经生理中的作用， 线粒体和病理后遗症。 这些的重要性 研究的最终目标是最大限度地减少窒息后CNS损伤 具体的治疗干预。

The goal of these studies is to continue work in the neonatal lamb post asphyxia model to pursue an understanding of mechanisms of perinatal brain injury. One set of studies is designed to examine the response of the cerebral circulation to hypocarbia in the "stressed" newborn lamb. Utilizing radiolabelled microsphere methodology and a sagittal sinus catheter to sample cerebral venous drainage, cerebral blood flow, 02 delivery, 02 consumption, and fractional 02 extraction will be measured or calculated. The first of these studies will examine the response of the cerebral circulation to hypocarbia in the post asphyxia newborn lamb while the second set will examine the same issue in a newly developed newborn lamb pulmonary hypertension model. Hyperventilation is used clinically most frequently in asphyxiated infants with pulmonary hypertension. These studies will go a long way towards assessing the safety of hyperventilation therapy in sick newborn infants. The other 3 studies will consider mechanisms of brain injury after asphyxia. The central hypothesis is that much of the brain injury associated with asphyxia occurs after rather than during the event. These studies will utilize the newborn lamb post asphyxia model. One set of studies will evaluate developmental differences in post asphyxia mitochondria function. A second study will assess neurophysiologic and pathologic consequences of asphyxia while the third group of studies will assess the effect of preasphyxia glucose concentration on neurophysiologic and pathologic sequelae of asphyxia and on post asphyxia mitochondria function. An underlying theme in many of these studies will be the role of oxygen free radicals in post the asphyxia neurophysiologic, mitochondrial, and pathologic sequelae. The importance of these studies is the ultimate goal of minimizing post asphyxia CNS injury with specific therapeutic interventions.