de Azeredo F A
Laboratorio de Biociencias, Universidade Federal Fluminense, Niteroi, Brazil.
Metab Brain Dis. 1991 Jun;6(2):75-82. doi: 10.1007/BF00999905.
The in vitro preparation of the chick retina can be used to show the occurrence of transient changes in the intracellular pH and of energy metabolites which occurs during spreading depression (SD). There is an initial increase in intracellular pH associated with elevated values for ADP, P-Creatine, lactate and pyruvate, an intermediary acid shift with increases in ATP values and decreases in ADP, and a late alkaline rebound where P-Creatine levels are reduced and the content of ADP and lactate are elevated. These transient changes in intracellular pH observed during SD, when correlated to the levels of energy metabolites, supports the hypothesis that the intracellular pH can be used by the tissue as a mechanism to rapidly modify the metabolic activities of neurons and glial cells. We suggest that the first alkaline shift is caused by glial cells and the intermediary acid shift by neurons. However, a specific cell could not be pointed out as responsible for the late alkaline shift but it could explain the refractoriness of the neurons during the phenomenon.
鸡视网膜的体外制备可用于显示在扩散性抑制（SD）期间细胞内pH值和能量代谢物的瞬时变化。最初细胞内pH值升高，同时ADP、磷酸肌酸、乳酸和丙酮酸值升高；中间出现酸性转变，ATP值增加，ADP值降低；后期出现碱性反弹，磷酸肌酸水平降低，ADP和乳酸含量升高。在SD期间观察到的细胞内pH值的这些瞬时变化，与能量代谢物水平相关，支持了这样一种假设，即细胞内pH值可被组织用作快速改变神经元和神经胶质细胞代谢活动的一种机制。我们认为，第一次碱性转变是由神经胶质细胞引起的，中间的酸性转变是由神经元引起的。然而，无法指出是哪种特定细胞导致了后期的碱性转变，但这可以解释该现象期间神经元的不应性。
