The in vivo effect of lipopolysaccharide on Na+,K+-ATPase catalytic (alpha) subunit isoforms in rat sciatic nerve

The Na+, K+-ATPase catalytic (alpha) subunit in sciatic nerve of lipopolysaccharide (endotoxin, LPS)-treated rat was investigated. Using Western blot to determine subunit isoform polypeptide levels in rat sciatic nerve, we found a substantial reduction in alpha 1 polypeptide, but not that of alpha 2 and alpha 3 polypeptides, after the administration of LPS. Moreover, when rats were treated with polymyxin B (a LPS neutralizer) and N-G-nitro-L-arginine (an inhibitor of nitric oxide (NO) synthase), the effects of LPS were reversed. These results implicate a specific marked deficit in alpha 1 subunit isoform of Na+,K+-ATPase in the pathogenesis of neuropathy during endotoxemia, through, at least in part, the L-arginine/NO pathway. (C) 1997 Elsevier Science Ireland Ltd.