Reserpine処置動物の血管条辺縁細胞Na-K ATPase活性に対するL-threo-DOPSの影響

抄録

Na-K ATPase in the stria vascularis is known to participate in the active transport of Na⁺ and K⁺ ions, and plays essential role in producing cochlear endolymph. The mechanisms that control or maintain the stria vascularis function, however, remain unclear. In the present study, the K-NPPase activity, the second component of the Na-K ATPase complex, in the marginal cells was cytochemically investigated after reserpine and L-threo-DOPS administration. K-NPPase activity was completely inhibited after treatment with reserpine, whereas, following reserpine and L-threo-DOPS treatment, enzyme activity was detectable. As reserpine is an adrenergic neuron blocker, and L-threo DOPS is the precursor of L-noradrenaline, noradrenaline converted from L-threo DOPS was able to restore K-NPPase activity in the reserpine-treated animals. The present result suggests that catecholamines may play an essential role in the maintenance or control of the Na-K ATPase activity, and that the stria vascularis may be one of the target organs of catecholamines.