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

The Na +, K +-ATPase catalytic ( α) 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 α1 polypeptide, but not that of α2 and α3 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 α1 subunit isoform of Na +,K +-ATPase in the pathogenesis of neuropathy during endotoxemia, through, at least in part, the l-arginine/NO pathway.