Lithium normalizes elevated intracellular sodium.
BACKGROUND
Both mania and bipolar depression are characterized by elevations of intracellular sodium concentrations. This observation has been purported to be central to the pathophysiology of abnormal moods in bipolar illness. Reduction of sodium influx is a proposed shared mechanism of action of effective mood stabilizers, but direct documentation of this effect for lithium has never been demonstrated.


METHODS
Flame spectroscopic determinations of intracellular sodium concentration were performed in the human glioma cell line, LN292, after treatment with the sodium pump inhibitor, ouabain, and co-treatment with ouabain and lithium.


RESULTS
Ouabain 0.1 microM doubles the intracellular sodium concentration after 3 days. Pretreatment with lithium 1 mM for 1 week normalizes intracellular sodium.


CONCLUSIONS
This is the first demonstration that lithium can normalize abnormally elevated intracellular sodium levels. This may be an important mechanism of lithium action.
Huang
Xian
X
Mood Disorders Research Program, Department of Psychiatry and Behavioral Sciences, University of Louisville School of Medicine, Loiusville, KY 40292, USA.
Lei
Zhenmin
Z
El-Mallakh
Rif S
RS
D014150:Antipsychotic Agents / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000627:therapeutic use; D001714:Bipolar Disorder / Q000188:drug therapy*; D045744:Cell Line, Tumor; D005910:Glioma / Q000378:metabolism / Q000473:pathology; D006801:Humans; D017136:Ion Transport / Q000187:drug effects*; D016651:Lithium Carbonate / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000627:therapeutic use; D009474:Neurons / Q000378:metabolism; D010042:Ouabain / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use; D012964:Sodium / Q000037:antagonists & inhibitors*; D015222:Sodium Channels / Q000096:biosynthesis; D013057:Spectrum Analysis
D014150:Antipsychotic Agents; D015222:Sodium Channels; D016651:Lithium Carbonate; D010042:Ouabain; D012964:Sodium