Kanoh N, Kobayashi T, Okada T, Seguchi H
Department of Otolaryngology, Hyogo College of Medicine, Japan.
Eur Arch Otorhinolaryngol. 1994;251(4):238-40. doi: 10.1007/BF00628431.
Ouabain-sensitive, K(+)-dependent, p-nitrophenylphosphatase (K-NPPase) is the second dephosphorylative property of the Na-K ATPase complex. Localization of its activity in the horizontal portion of the facial nerve in 11 normal cats was studied ultracytochemically using a cerium-based method. The fine granular reaction product of the K-NPPase activity was observed on the cytoplasmic side of the axolemma of the axon cylinder. Enzyme activity was also detected on the cytoplasmic side of the plasma membrane of Schmidt-Lanterman incisures and nodes of Ranvier. No reaction product was detected on the periaxonal and outermost plasma membrane of Schwann cells and in the myelin sheath. In control tissue samples, enzyme activity was almost completely inhibited by 10 mM ouabain, and no reaction was noted in medium without K+. The present findings indicate that localization of Na-K ATPase in the cat facial nerve simulates that of other peripheral and cranial nerves.
哇巴因敏感的、钾离子依赖的对硝基苯磷酸酶（K-NPPase）是钠钾ATP酶复合体的第二种去磷酸化特性。采用基于铈的方法，通过超微细胞化学技术研究了11只正常猫面神经水平段中其活性的定位。在轴索圆柱体轴膜的胞质侧观察到K-NPPase活性的细颗粒反应产物。在施万细胞切迹和郎飞结的质膜胞质侧也检测到酶活性。在雪旺细胞的轴周和最外层质膜以及髓鞘中未检测到反应产物。在对照组织样本中，10 mM哇巴因几乎完全抑制了酶活性，在无钾离子的培养基中未观察到反应。目前的研究结果表明，猫面神经中钠钾ATP酶的定位与其他周围神经和颅神经相似。
