The effect of lithium on the incorporation of 32P-orthophosphate into synaptosomal phospholipids from rat brain.

Rats were treated with lithium added to the diet for five weeks (40 mmol LiCl/kg diet). The mean plasma lithium concentration was 0.48 mmol/l plasma, and the blood was drawn at 8 a.m. The brains were removed and synaptosomes were prepared according to the method of Gray & Whittaker (1962) and Bradford (1972). The synaptosomes were incubated for 120 min. with 32P-orthophosphate, either in a lithium-containing medium or in a lithium-free medium. The 32P-incorporation was lower in the synaptosomes from lithium-treated rats than the 32P-incorporation in synaptosomes from control rats regardless of the medium chosen. The results indicate that lithium treatment in vivo decreases the 32P-incorporation into synaptosomal phospholipids and that the effect remains after the removal of the lithium ion.