de Gandarias J M, Irazusta Astiazaran J, Varona A, Fernández D, Gil J, Casis L
Department of Physiology, Medical School, University of the Basque Country, Bilbao, Spain.
Arzneimittelforschung. 1999 Oct;49(10):816-9. doi: 10.1055/s-0031-1300507.
Lithium (CAS 7439-93-2) is being utilized widely for the treatment of manic-depressive illness. However, the neurochemical mechanism of the ion action still remains relatively obscure. In the present work, the effect of acute lithium administration on soluble and membrane-bound enkephalin-degrading tyrosine-aminopeptidase activities in discrete brain areas and the pituitary gland is described. Tyrosine-aminopeptidase activities have been measured fluorometrically using Tyr-beta-naphthylamide as substrate and puromycin as selective inhibitor of one of the two membrane activities. Soluble and membrane-bound puromycin-insensitive Tyr-aminopeptidase activities are greater in the pituitary gland after treatment with 5 and 10 meq/kg of lithium. It is suggested that these enzyme activities could play a part in the lithium action mechanism.
