[Influence of lithium on magnesium levels in the plasma, erythrocytes and brain of rats].

Intra peritoneal administration of LiCl to rat with a single dose or every day during a week shows that the correlation of brain Li with erythrocytes Li is better than the same correlation with plasmatic Li. With a single dose of Li the variation of the Li level doesn't give significant variations of Mg. With repetitive administrations of Li (near that which occurs in actual therapeutic treatment) we show (44 pairs of results with p less than 0.001) that the increase of Li in erythrocytes is correlated with a decrease of Mg in erythrocytes and an increase of this ion in plasma. The authors demonstrate that the nervous cells don't release Mg when Li get in the brain.