BARIUM REVERSES THE TRANSRETINAL POTASSIUM GRADIENT OF THE AMPHIBIAN RETINA
BARIUM REVERSES THE TRANSRETINAL POTASSIUM GRADIENT OF THE AMPHIBIAN RETINA
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DOI：
10.1016/0304-3940(87)90495-2
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发表时间：
1987-09-11
影响因子：
2.5
通讯作者：
MILLER, RF
中科院分区：
文献类型：
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作者：
COLEMAN, PA;CARRAS, PL;MILLER, RF
将氯化钡 (Ba2+) 添加到虎蝾螈灌注视网膜眼杯制剂的沐浴介质中。使用双筒电极分析视网膜电图（ERG）和视网膜内细胞外钾活性（[K+]o），其中一个电极对 K+ 具有离子选择性。 Ba2+ 对 ERG 的作用是减弱 c 波/慢 PIII 复合体。此外，Ba2+ 显着降低了外视网膜中的 [K+]o，足以逆转经视网膜钾梯度。这些发现与 Muller 细胞 K+ 通道的已知特性一起，构成了解释为什么 Ba2+ 会阻断缓慢的 PIII 而不是 ERG 的 b 波的基础。
Barium chloride (Ba2+) was added to the bathing medium of the perfused retina-eyecup preparation of the tiger salamander. The electroretinogram (ERG) and intraretinal extracellular potassium activity ([K+]o) were analyzed using a double-barrel electrode, one of which was ion-selective for K+. The action of Ba2+ on the ERG was to attenuate the c-wave/slow PIII complex. In addition, Ba2+ dramatically decreased the [K+]o in the outer retina, enough to reverse the transretinal potassium gradient. These findings, together with the known properties of Muller cell K+ channels, form the basis of an explanation of why Ba2+ blocks slow PIII and not the b-wave of the ERG.