Kanoh N
Department of Otolaryngology, Hyogo College of Medicine, Nishinomiya, Japan.
Ann Otol Rhinol Laryngol. 1999 Apr;108(4):345-8. doi: 10.1177/000348949910800405.
In strial marginal cells, Na+/K(+)-ATPase activity is abundant, and contributes to maintain the characteristic electrolyte composition of the cochlear endolymph. In the present study, to clarify the relationship between epinephrine and strial Na+/K(+)-ATPase activity, the ouabain-sensitive, K+-dependent p-nitrophenylphosphatase (K(+)-NPPase) activity of strial marginal cells was investigated with a cerium-based method in normal guinea pigs and guinea pigs treated with reserpine, epinephrine, and reserpine plus epinephrine. In our previous study, K(+)-NPPase activity had almost completely decreased 3 to 20 days after reserpine administration. In the present study, at 10 days after reserpinization and following repeated epinephrine treatment, enzyme activity was detectable. These results suggest that exogenous epinephrine was able to restore strial K(+)-NPPase activity in the reserpine-treated animals, and that epinephrine might increase strial Na+/K(+)-ATPase activity.
血管纹边缘细胞中，Na⁺/K⁺-ATP酶活性丰富，有助于维持耳蜗内淋巴的特征性电解质组成。在本研究中，为阐明肾上腺素与血管纹Na⁺/K⁺-ATP酶活性之间的关系，采用铈基方法，在正常豚鼠以及用利血平、肾上腺素、利血平加肾上腺素处理的豚鼠中，研究了血管纹边缘细胞的哇巴因敏感、K⁺依赖性对硝基苯磷酸酶（K⁺-NPPase）活性。在我们之前的研究中，利血平给药后3至20天，K⁺-NPPase活性几乎完全降低。在本研究中，利血平化10天后并经反复肾上腺素处理后，可检测到酶活性。这些结果表明，外源性肾上腺素能够恢复利血平处理动物的血管纹K⁺-NPPase活性，且肾上腺素可能会增加血管纹Na⁺/K⁺-ATP酶活性。
