Lubec B, Dell'Anna E, Fang-Kircher S, Marx M, Herrera-Marschitz M, Lubec G
University of Vienna, Department of Neonatology, Austria.
J Investig Med. 1997 Jun;45(5):284-94.
Acidosis, energy depletion, overstimulation by excitatory amino acids, and free radical-mediated reactions are the major, current concepts for the explanation of damage and death resulting from asphyxia. Impaired protein phosphorylation by protein kinase C represents another mechanism incriminated in cell death.
We used a nonsophisticated perinatal asphyxia model to study brain (frontal cortex) pH, ATP, protein kinases PKC, PKA, and cyclin-dependent kinase. We used o-tyrosine, a marker for hydroxyl radical attack, and LPO 586, a spectrophotometric assay, to study lipid peroxidation products. The antioxidant enzymes catalase, superoxide dismutase, and glutathione peroxidase were used in the frontal cortex. In addition, a cell death ELISA and histology to evaluate cell death were performed.
Brain pH and protein kinases were decreasing with the length of the asphyctic periods, and energy depletion was shown by a drop of ATP levels, whereas no evidence for the involvement of free radical-mediated mechanisms was obtained. Cell death was shown by the cell death ELISA as early as 10 minutes after the asphyctic period, and histologically, cell death could be revealed but not before day 8 after asphyxia.
Acidosis and/or impaired protein kinases, but not free radical mechanisms, may play a role in the pathobiochemistry of cell death in neonatal asphyxia of the rat.
酸中毒、能量耗竭、兴奋性氨基酸的过度刺激以及自由基介导的反应是目前用于解释窒息所致损伤和死亡的主要概念。蛋白激酶C介导的蛋白磷酸化受损是另一种与细胞死亡有关的机制。
我们使用一种简单的围产期窒息模型来研究脑（额叶皮质）的pH值、三磷酸腺苷（ATP）、蛋白激酶蛋白激酶C（PKC）、蛋白激酶A（PKA）和细胞周期蛋白依赖性激酶。我们使用邻酪氨酸（一种羟基自由基攻击的标志物）和LPO 586（一种分光光度测定法）来研究脂质过氧化产物。在额叶皮质中使用抗氧化酶过氧化氢酶、超氧化物歧化酶和谷胱甘肽过氧化物酶。此外，还进行了细胞死亡酶联免疫吸附测定（ELISA）和组织学检查以评估细胞死亡情况。
随着窒息时间的延长，脑pH值和蛋白激酶水平下降，ATP水平下降表明能量耗竭，而未获得自由基介导机制参与的证据。细胞死亡ELISA显示，早在窒息期后10分钟就出现了细胞死亡，组织学上，直到窒息后第8天才发现细胞死亡。
酸中毒和/或蛋白激酶受损，而非自由基机制，可能在大鼠新生儿窒息细胞死亡的病理生物化学过程中起作用。
