McGrail K M, Sweadner K J
J Neurosci. 1986 May;6(5):1272-83. doi: 10.1523/JNEUROSCI.06-05-01272.1986.
Two isozymes of the Na,K-ATPase are made in the brain and retina. Antisera have been produced that contain antibodies specific for each of the catalytic subunits of the two isozymes, alpha and alpha(+) (Sweadner & Gilkeson, 1985a). To determine which classes of cells express which form of the Na,K-ATPase, and whether cells can express both forms, the antisera were used to stain sections of the rat retina and dissociated retinal cells by indirect immunofluorescence. In sections of the retina, bright stain specific for both isozymes was seen in the inner segments of the photoreceptor cells, the outer and inner plexiform layers, and in the ganglion cell axons. Cell bodies were outlined in the inner nuclear layer. Stain specific for the alpha isozyme was seen in adhering pigment epithelium and at the position of the apical processes of the Müller glial cells. In sections of the optic nerve, the nerve itself stained for both isozymes, although the stain for the alpha(+) isozyme was stronger. The sheath, in contrast, stained selectively for the alpha isozyme. Cells were dissociated from the retina, and they were identified by their morphology and by cell class-specific monoclonal antibodies. Müller glial cells were found to stain brightly for only the alpha isozyme, while horizontal and ganglion cells stained brightly for both isozymes. Bipolar cells stained faintly for only the alpha(+) isozyme, while amacrine cells stained faintly for both isozymes. The evidence indicates that different kinds of neurons can express one or both isozymes of the Na,K-ATPase, and at quantitatively different levels.
钠钾-ATP酶的两种同工酶在大脑和视网膜中合成。已经制备了抗血清，其中含有针对这两种同工酶的每个催化亚基α和α⁺的特异性抗体（斯韦德纳和吉尔克森，1985年a）。为了确定哪些细胞类别表达钠钾-ATP酶的哪种形式，以及细胞是否可以同时表达两种形式，使用抗血清通过间接免疫荧光对大鼠视网膜切片和分离的视网膜细胞进行染色。在视网膜切片中，在光感受器细胞的内段、外网状层和内网状层以及神经节细胞轴突中可见对两种同工酶均特异的明亮染色。细胞核层勾勒出细胞体。在附着的色素上皮和穆勒神经胶质细胞顶端突起的位置可见对α同工酶特异的染色。在视神经切片中，神经本身对两种同工酶均有染色，尽管对α⁺同工酶的染色更强。相比之下，神经鞘对α同工酶有选择性染色。从视网膜中分离出细胞，并通过其形态和细胞类别特异性单克隆抗体对其进行鉴定。发现穆勒神经胶质细胞仅对α同工酶有明亮染色，而水平细胞和神经节细胞对两种同工酶均有明亮染色。双极细胞仅对α⁺同工酶有微弱染色，而无长突细胞对两种同工酶均有微弱染色。证据表明，不同种类的神经元可以表达钠钾-ATP酶的一种或两种同工酶，并且表达量不同。
