Distribution of alpha 1 subunit isoform of (Na,K)-ATPase in the rat spinal cord

Abstract

Three isoforms of the alpha subunit of (Na,K)-ATPase have been identified in the rat central nervous system. Using a probe specific for the alpha 1 isoform, mRNA levels were measured from five sections of the rat spinal cord using slot blot techniques. Assigning a value of 1 to the slope obtained from the cervical section, the upper thoracic section was 2.6 times higher; the midthoracic section was 4.5 times higher; the lower thoracic section was 2.6 times higher; and the lumbar section was 1.7 times higher. The results suggest that alpha 1 isoform mRNA levels are not uniform throughout the spinal cord. In situ hybridization techniques showed that alpha 1 isoform mRNA was diffusely abundant in glial and central canal ependymal cells, while labeled neurons were localized exclusively in laterally located anterior horn neurons in cervical, thoracic, and lumbar segments and in ventromedial neurons in mid-thoracic spinal cord. Also, dorsal root ganglia neurons were extensively labeled at all segments.

Differential expression of Na,K-ATPase ?-isoform mRNAs in aging rat cerebellum

“…The large neurons are usually those that express a3 alone. This is similar to the situation observed in the spinal cord Sayers et al, 1994). However, it is difficult to explain the isoform selectivity of neurons based only on neurotransmitters, size, connectivity, or location.…”

Two Drosophila nervous system antigens, Nervana 1 and 2, are homologous to the beta subunit of Na+,K(+)-ATPase.

“…Other species also contain multiple forms of Na+,K+-ATPase 13 subunit (28,29,33,34), although neuron-specific forms have not yet been described. AMOG, the rat Na+,K+-ATPase 2 subunit, is preferentially expressed by glial cells in the nervous system (33,35), while several other studies have established the tissue-specific and in some cases cell typespecific expression of the catalytic Na+,K+-ATPase a subunit in a variety of species (29,36,37). It is somewhat surprising that we do not detect Nrvl or Nrv2 expression in other types of Drosophila tissue, such as muscle, which also contains Na+,K+-ATPase (38).…”

The β3 subunit of the Na+,K+-ATPase mediates variable nociceptive sensitivity in the formalin test

“…It is well known that the Na + ,K + -ATPase is found throughout the nociceptive axis [48] and is absolutely critical to neuronal function [26]. However, only a very limited number of studies—with somewhat disparate findings—have examined the role of the Na + ,K + -ATPase in modulating pain.…”