Platelet membrane phospholipids in euthymic bipolar disorder patients: are they affected by lithium treatment?

Biol Psychiatry. 1999 Feb 15;45(4):453-7. doi: 10.1016/s0006-3223(98)00048-1.


Background: Abnormalities in cell membrane processes and intracellular signal transduction pathways may be implicated in the pathophysiology of bipolar disorder. In this study, we attempted to investigate, in euthymic bipolar patients: 1) in vivo signal transduction abnormalities of the phosphatidylinositol pathway in platelets; and 2) possible in vivo effects of lithium treatment on platelet membrane phospholipids.

Methods: We determined the relative absorbances of eight individual classes of platelet membrane phospholipids, using two-dimensional thin-layer chromatography in high-performance plates, followed by scanning laser densitometry, in a group of 10 lithium-treated euthymic bipolar patients and 11 normal controls.

Results: The mean relative absorbance of phosphatidyl-inositol-4,5-bisphosphate (PIP2) was lower in the patient group (0.29 +/- 0.08% vs. 0.39 +/- 0.12%; t = 2.35, df = 19, p = .03); no significant differences between patients and controls were found for the other phospholipids.

Conclusions: This study provides in vivo evidence that bipolar patients on lithium treatment exhibit a decreased relative amount of PIP2 in the platelet cell membranes compared to normal controls.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Bipolar Disorder* / blood
  • Bipolar Disorder* / drug therapy
  • Bipolar Disorder* / physiopathology
  • Blood Platelets / drug effects*
  • Blood Platelets / metabolism
  • Case-Control Studies
  • Densitometry
  • Female
  • Humans
  • Lithium / pharmacology*
  • Male
  • Phosphatidylinositol 4,5-Diphosphate / metabolism*
  • Phospholipids / metabolism
  • Signal Transduction* / drug effects
  • Signal Transduction* / physiology


  • Phosphatidylinositol 4,5-Diphosphate
  • Phospholipids
  • Lithium