Mild hyperhomocysteinemia reduces the activity and immunocontent, but does not alter the gene expression, of catalytic alpha subunits of cerebral Na+, K+-ATPase

作者：Scherer Emilene B S; Loureiro Samanta O; Vuaden Fernanda C; Schmitz Felipe; Kolling Janaina; Siebert Cassiana; Savio Luiz Eduardo B; Schweinberger Bruna M; Bogo Mauricio R; Bonan Carla D; Wyse Angela T S^*

来源：Molecular and Cellular Biochemistry, 2013, 378(1-2): 91-97.

DOI：10.1007/s11010-013-1598-6

• Mild hyperhomocysteinemia
• Na+,K+-ATPase
• Catalytic subunits
• Gene expression
• Cerebral structures

Na+,K+-ATPase is a membrane protein which plays a key role in the maintenance of ion homeostasis that is necessary to neuronal excitability, secondary transport and neurotransmitter uptake. Mild hyperhomocysteinemia leads to several clinical manifestations and particularly cerebral diseases; however, little is known about the mechanisms of homocysteine on cerebral Na+,K+-ATPase. In the present study, we investigated the effect of mild hyperhomocysteinemia on the activity, the immunocontent of catalytic subunits (alpha(1), alpha(2), and alpha(3)) and the gene expression of this enzyme. We used the experimental model of mild hyperhomocysteinemia that was induced by homocysteine administration (0.03 mu mol/g of body weight) twice a day, from the 30th to the 60th postpartum day. Controls received saline in the same volumes. Results showed that mild hyperhomocysteinemia significantly decreased the activity and the immunocontent of the a1 and alpha(2) subunits of the Na+,K+-ATPase in cerebral cortex and hippocampus of adult rats. On the other hand, we did not observe any change in levels of Na+,K+-ATPase mRNA transcripts in such cerebral structures of rats after chronic exposure to homocysteine. The present findings support that the homocysteine modulates the Na+,K+-ATPase and this could be associated, at least in part, with the risk to the development of cerebral diseases in individuals with mild hyperhomocysteinemia.

• 出版日期2013-6