Localization of Na,K‐ATPase α/β Isoforms in Rat Sciatic Nerves : Effect of Diabetes and Fish Oil Treatment

Abstract
: The localization of the Na,K-ATPase isoenzymes in sciatic nerve remains controversial, as well as diabetes-induced changes in Na,K-ATPase isoforms. Some of these changes could be prevented by fish oil therapy. The aim of this study was to determine by confocal microscopy the distribution of Na,K-ATPase isoforms (α1, α2, α3, β1, and β2) in the sciatic nerve, the changes induced by diabetes, and the preventive effect of fish oil in diabetic neuropathy. This study was performed in three groups of rats. In the first two groups, diabetes was induced by streptozotocin and rats were supplemented daily with fish oil or olive oil at a dosage of 0.5 g/kg of body weight. The third one was a control group that was supplemented with olive oil. Five antibodies against specific epitopes of Na,K-ATPase isoenzymes were applied to stained dissociated nerve fibers with fluorescent secondary antibodies. The five isoenzymes were documented in nonspecific regions, Schwann cells (myelin), and the node of Ranvier. The localization of the α1, α2, and β1 isoenzymes was not affected by diabetes. In contrast, diabetes induced a decrease of the α2 subunit (p < 0.05) and an up-regulation of the β2 subunit (p < 0.05). These modifications were noted in both regions for α2 and were localized at the myelin domain only for the β2. Fish oil supplementation prevented the diabetes-induced changes in the α2 subunit with an additional up-regulation. The β2 subunit was not modified. A phenotypic change similar to nerve injury was induced by diabetes. Fish oil supplementation partially prevented some of these changes.

This publication has 45 references indexed in Scilit: