BIOCHEMICAL EVOLUTION OF ISCHEMIC BRAIN DAMAGE

本研究的目的是确定组织酸中毒是否 在缺血性损伤的发展中起关键作用，如果是这样， 哪些生化机制。 使用可逆的，单侧的 在缺氧缺血的小鼠中，我们将首先开发一个区域， 脑pH值的定量方法。第二，脑pH值的缺血性改变 与缺氧缺血时乳酸的积累有关 以及缺血后能量代谢的恢复。 第三，pH值变化 在缺氧-缺血期间，将通过（a）施用CO2和（B） 通过部分抑制糖酵解途径， 恢复能量代谢。 最后，糖酵解的缺血性变化 除乳酸盐外的中间体将在葡萄糖预处理的 动物检测与酸中毒无关的有害变化。 的 第二个主要目标是确定生物化学过程， 受酸中毒/葡萄糖预处理影响。 因为NADH是酸不稳定的，我们 将测量大脑中NADH、NAD+及其降解产物的水平， 使用酶法和高效液相色谱法（HPLC）。 此外，我们将尝试通过以下方式更改NAD池的大小： 给予前体、烟酰胺和假前体， 6-氨基烟酰胺。 酸/糖预处理对脑组织的影响 腺苷酸、鸟苷酸、尿苷酸和胞苷酸水平 将使用HPLC测定缺氧-缺血。 最后，降解剂 测定缺氧缺血脑组织中酸性磷酸酶活性 使用体外和体内方法。

The goal of this investigation is to determine whether tissue acidosis plays a critical role in the development of ischemic damage and, if so, by which biochemical mechanisms. Using a model of reversible, unilateral hypoxia-ischemia in the mouse, we will first develop a regional, quantitative method for brain pH. Second, ischemic alterations of brain pH will be correlated with the accumulation of lactate during hypoxia-ischemia and with postischemic recovery of energy metabolism. Third, the pH changes during hypoxia-ischemia will be modified (a) by administering CO2 and (b) by partially inhibiting the glycolytic pathway in order to alter the recovery of energy metabolism. Finally, the ischemic change in glycolytic intermediates other than lactate will be determined in glucose-pretreated animals to detect deleterious alterations not related to acidosis. The second major aim is to identify the biochemical processes which are affected by acidosis/glucose-pretreatment. Because NADH is acid-labile, we will measure brain levels of NADH, NAD+, and their degradation products using enzymatic methods and high performance liquid chromatography (HPLC). In addition, we will attempt to alter the size of the NAD pool by administering the precursor, nicotinamide, and a false precursor, 6-amino-nicotinamide. The effect of acidosis/glucose-pretreatment on brain levels of Adenyl, Guanyl, Uridyl, and Cytidyl Nucleotides during and after hypoxia-ischemia will be determined using HPLC. Finally, the degradative activity of acid phosphatase will be assayed in hypoxic-ischemic brain using both in vitro and in vivo methods.