Effect of lithium treatments on the tyrosine-aminopeptidase activities in the rat brain and the pituitary gland.
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.
de Gandarias
J M
JM
Department of Physiology, Medical School, University of the Basque Country, Bilbao, Spain.
Irazusta Astiazaran
J
J
Varona
A
A
Fernández
D
D
Gil
J
J
Casis
L
L
D000626:Aminopeptidases / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000201:enzymology*; D004745:Enkephalins / Q000096:biosynthesis; D008094:Lithium / Q000494:pharmacology*; D008297:Male; D008566:Membranes / Q000187:drug effects / Q000201:enzymology; D009419:Nerve Tissue Proteins / Q000096:biosynthesis; D018377:Neurotransmitter Agents / Q000494:pharmacology; D010902:Pituitary Gland / Q000187:drug effects / Q000201:enzymology*; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D011691:Puromycin / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013050:Spectrometry, Fluorescence; D014443:Tyrosine / Q000037:antagonists & inhibitors / Q000378:metabolism*
D004745:Enkephalins; D009419:Nerve Tissue Proteins; D018377:Neurotransmitter Agents; D011500:Protein Synthesis Inhibitors; D014443:Tyrosine; D011691:Puromycin; D008094:Lithium; D000626:Aminopeptidases; C086415:tyrosyl aminopeptidase