Increased inositol-monophosphatase activity by lithium treatment in bipolar patients.
Inhibition of inositol monophosphatase (IMPase) enzyme is the target mechanism of action of lithium. However, increased activity of mRNA levels by lithium has been reported. These two diverse effects were shown after relatively short periods of lithium administration. The aim of this study was to observe the effect of prolonged use of lithium on IMPase activity. The authors investigated IMPase activities in fresh erythrocytes and leukocytes in 63 bipolar patients (42 euthymic, 8 depressive, 13 manic episodes) and 16 control subjects. We found that erythrocyte IMPase activity was higher in lithium treated euthymic patients than non-lithium treated patients. The duration of lithium use was positively correlated with leukocyte IMPase activity. Increased IMPase activity by chronic lithium use suggests an up-regulation of the enzyme activity.
Kaya
Nezaket
N
Department of Psychiatry, School of Medicine, Dokuz Eylul University, Balcova, 35340 Izmir, Turkey.
Resmi
Halil
H
Ozerdem
Aysegul
A
Guner
Gul
G
Tunca
Zeliha
Z
D000328:Adult; D018692:Antimanic Agents / Q000009:adverse effects* / Q000097:blood / Q000627:therapeutic use; D001714:Bipolar Disorder / Q000188:drug therapy / Q000201:enzymology*; D004305:Dose-Response Relationship, Drug; D004912:Erythrocytes / Q000201:enzymology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007962:Leukocytes / Q000201:enzymology; D008094:Lithium / Q000009:adverse effects* / Q000097:blood / Q000627:therapeutic use; D008297:Male; D010744:Phosphoric Monoester Hydrolases / Q000097:blood*
D018692:Antimanic Agents; D008094:Lithium; D010744:Phosphoric Monoester Hydrolases; C021822:myo-inositol-1 (or 4)-monophosphatase