Platelet protein kinase C alpha levels in drug-free and lithium-treated subjects with bipolar disorder

Recent studies suggest that protein kinase C (PKC), particularly the alpha isoform, plays an important role in the action of lithium. There is, howeve r, little evidence from patients with bipolar disorder (BD) to support this effect. The present investigation carried out comparative studies of PKC l evels in platelets obtained from ED subjects including those with and witho ut lithium treatment. All subjects met DSM-IV criteria for ED type I confir med by structured interview (SCID-IV). Levels of PKC-alpha isoform in plate lets from controls and from ED subjects were measured with immunoblotting a nalysis. No significant differences were found between controls, drug-free or lithium-treated ED subjects on membrane or cytosolic levels of PKC-alpha or in the membrane-to-cytosol ratio of this protein. The present study sug gests that levels of PKC-alpha do not change in the peripheral tissues of E D subjects with or without lithium treatment.