Dolapchieva S D
Department of Anatomy and Histology, Medical University, Sofia, Bulgaria.
Membr Cell Biol. 1998;12(3):355-61.
The data concerning the distribution of Na+,K(+)-ATPase alpha and beta subunit isoforms in the spinal cord and partly in the motor neurons of the ventral horns are limited. The lumbo-sacral portion of the spinal cord of adult rats was immunotested with polyclonal antibodies (UBI, NY) specific for alpha 1, alpha 2, alpha 3 and beta 1, beta 2 isoforms. After paraformaldehyde perfusion and postfixation, free-floating 50 microns thick vibratome sections were immunostained with Vectastatin Elite ABC. Sites of bound primary antibodies were visualized by incubation in DAB-H2O2 substrate medium. The histochemical technique revealed immunostaining for all five isoforms of Na+,K(+)-ATPase in the motor neurons. The findings show a principal similarity in the distribution pattern of the immuno-like reactivity for alpha 1 and alpha 2 isoforms, the staining of the pericarya being more or less continuous with that of the microenvironment. The immunostaining for beta 2 (in comparison with alpha 1 and alpha 2) outlines the pericarya of the motor neurons slightly better, whereas the staining for beta 1 outlines them extremely sharply. The immunostaining pattern for the alpha 3 isoform differs considerably from that for the other isoforms. The immuno-like reactivity for this isoform is concentrated at the surface of the pericarya and processes of the motor neurons. Accumulation of alpha 3 immunoreactivity on the surface of the motor neurons might reflect the intensive traffic of the alpha 3 isoform from the pericaryon to the plasma membrane and the processes of the neurons. The findings from the investigations performed here support the opinion, that, in addition to the conventional catalytic role in Na+,K(+)-ATPase activity, Na+,K(+)-ATPase isozymes play a part in different specific phenomena in the nervous system.
关于钠钾ATP酶α和β亚基同工型在脊髓以及部分腹角运动神经元中的分布数据有限。用针对α1、α2、α3以及β1、β2同工型的多克隆抗体（UBI、NY）对成年大鼠脊髓腰骶部进行免疫检测。经多聚甲醛灌注和后固定后，用Vectastatin Elite ABC对50微米厚的游离振动切片进行免疫染色。通过在DAB-H2O2底物培养基中孵育来观察结合的一抗位点。组织化学技术显示运动神经元中钠钾ATP酶的所有五种同工型均有免疫染色。结果表明，α1和α2同工型的免疫样反应分布模式基本相似，胞体染色与微环境染色或多或少连续。与α1和α2相比，β2的免疫染色能稍好地勾勒出运动神经元的胞体，而β1的染色则能极其清晰地勾勒出它们。α3同工型的免疫染色模式与其他同工型有很大不同。该同工型的免疫样反应集中在运动神经元胞体表面和突起上。运动神经元表面α3免疫反应性的积累可能反映了α3同工型从胞体到神经元质膜和突起的大量运输。此处进行的研究结果支持这样一种观点，即除了在钠钾ATP酶活性中具有传统催化作用外，钠钾ATP酶同工型在神经系统的不同特定现象中也发挥作用。
