Calcium-dependent modulation by ethanol of mouse synaptosomal pyroglutamyl aminopeptidase activity under basal and K(+)-stimulated conditions.

Abstract

We studied the in vitro effects of ethanol (25, 50 and 100 mM) on pyroglutamyl aminopeptidase activity (pGluAP), which has been reported as thyrotrophin-releasing-hormone-degrading activity. pGluAP was measured in presence or absence of calcium, under basal and K(+)-stimulated conditions, in synaptosomes and their incubation supernatant, using pyroglutamyl-beta-naphthylamide as substrate. In basal conditions, in synaptosomes, pGluAP was inhibited by ethanol in a calcium-independent way. In the supernatant, the response differed depending on the concentration of ethanol. Depolarization with K(+) modified pGluAP in synaptosomes and supernatant depending on the presence or not of calcium. In synaptosomes, in absence of calcium, the activity was inhibited at the highest concentrations of ethanol. In contrast, in the supernatant, under depolarizing conditions, ethanol increases pGluAP in absence of calcium. These changes may be in part responsible of the behavioural changes associated to alcohol intake.

Cite this paper

@article{Mayas2000CalciumdependentMB, title={Calcium-dependent modulation by ethanol of mouse synaptosomal pyroglutamyl aminopeptidase activity under basal and K(+)-stimulated conditions.}, author={Mar{\'i}a Dolores Mayas and Mar{\'i}a Jes{\'u}s Ram{\'i}rez-Exp{\'o}sito and M Jose Garcia and G K Tsuboyama and M Ram{\'i}rez and Jos{\'e} Manuel Mart{\'i}nez-Martos}, journal={Neuroscience letters}, year={2000}, volume={293 3}, pages={199-202} }