ALPHA2 ISOFORM OF THE NA,K-ADENOSINE TRIPHOSPHATASE IS REDUCED IN TEMPORAL CORTEX OF BIPOLAR INDIVIDUALS

Background: The pathophysiology of bipolar illness has been associated with changes in transmembrane ion flux and redistribution of biologic ally active ions. The recent identification of multiple isoforms of Na ,K-adenosine triphosphatase (ATPase) alpha and beta subunits raises th e possibility of altered pump isoform expression. Methods: We determin ed Na,K-ATPase alpha subunit expression in postmortem temporal col tex gray matter from individuals suffering from bipolar disorder, schizoa ffective disorder, schizophrenia, and matched normal controls. Quantif ication of isoform expression was accomplished via densitometric scann ing of Western blots utilizing isoform-specific antibodies. Results: B ipolar individuals exhibited a significant reduction in the abundance of the alpha 2 isoform of Na,K-ATPase compared to normal controls. Sch izophrenic and schizoaffective brains were not. significantly differen t from normal controls. Conclusion: These data suggest that previously observed abnormalities in regulation and distribution of ions in bipo lar illness may be related to specific alpha 2 dysregulation. Publishe d 1998 Society of Biological Psychiatry.