Lithium regulation of protein phosphorylation in rat cerebral cortex slices in vitro.
The aim of the present study was to evaluate the direct effect of Li+ and Na+-Li+ exchange on protein phosphorylation in rat cerebral cortex slices incubated in Krebs Ringer medium. When Na+ concentration was varied in the incubation medium, either by replacement with Li+ or sucrose, a variable effect on [32P] phosphate incorporation into proteins was observed. Protein phosphorylation in cerebral cortex slices was very low in the absence of Na+, and some dependence of phosphorylating system of neural tissue on extra cellular concentration of Na+ was evident. Lithium was not able to replace sodium as far as protein phosphorylation in cortical slices is concerned. Ouabain was more effective in a Li+ containing medium in inhibiting protein phosphorylation, presumably due to improper functioning of the sodium pump.
Singh
T D
TD
Department of Biochemistry, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
Shankar
R
R
D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D066298:In Vitro Techniques; D008094:Lithium / Q000378:metabolism / Q000494:pharmacology*; D010042:Ouabain / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects; D011506:Proteins / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012964:Sodium / Q000378:metabolism / Q000494:pharmacology
D004791:Enzyme Inhibitors; D011506:Proteins; D010042:Ouabain; D008094:Lithium; D012964:Sodium