Lecain E, Robert J C, Thomas A, Tran Ba Huy P
Neurobiologie des réseaux sensorimoteurs, UPRESA 7060, Laboratoire d'Otologie Expérimentale, Faculté Lariboisere-St-Louis, Paris, France.
Hear Res. 2000 Nov;149(1-2):147-54. doi: 10.1016/s0378-5955(00)00174-x.
Inner ear fluids and cerebrospinal fluid show remarkably stable ionic concentrations, particularly that of K(+) and H(+), but the mechanisms which control the homeostasis of these media are not well understood. We investigated a possible role of the gastric H, K-ATPase (gH,K-ATPase) pump in this control since this pump is known to be expressed in other tissues than gastric parietal cells. Here, we show by reverse transcription-polymerase chain reaction that the rat gH,K-ATPase alpha- and beta-subunits are expressed in the inner ear (lateral wall, organ of Corti and spiral ganglion cells), while only the alpha-subunit is expressed in the choroid plexus (CP). The presence of the alpha-subunit in the inner ear and CP was confirmed by immunoblotting. Immunohistochemistry localized this protein in the intermediate cells of the stria vascularis, in the spiral ligament and the spiral ganglion. gH,K-ATPase could be involved in the maintenance of H(+) and K(+) equilibria in cerebrospinal and labyrinthine fluids.
内耳液和脑脊液显示出显著稳定的离子浓度，尤其是钾离子（K⁺）和氢离子（H⁺）的浓度，但控制这些介质稳态的机制尚未完全清楚。我们研究了胃H⁺，K⁺ -ATP酶（gH，K-ATP酶）泵在这种控制中的可能作用，因为已知该泵在胃壁细胞以外的其他组织中表达。在此，我们通过逆转录-聚合酶链反应表明，大鼠gH，K-ATP酶的α和β亚基在内耳（外侧壁、柯蒂氏器和螺旋神经节细胞）中表达，而在脉络丛（CP）中仅表达α亚基。免疫印迹证实了内耳和脉络丛中α亚基的存在。免疫组织化学将该蛋白定位在血管纹的中间细胞、螺旋韧带和螺旋神经节中。gH，K-ATP酶可能参与脑脊液和内耳液中H⁺和K⁺平衡的维持。
