Poster
# 21
Poster |
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6th Internet World Congress for Biomedical Sciences |
María Dolores Mayas-Torres(1), José Manuel Martínez-Martos(2), María Jesús Ramírez-Expósito(3), María Jesús García-López(4), Isabel Prieto-Gómez(5), Garbiñe Arechaga-Maza(6), Manuel Ramírez-Sánchez(7)
(1)(2)(4)(5)(6)(7)Unit of Physiology. University of Jaén - Jaén. Spain
(3)Unit of Physiology. University of Jaen - Jaén. Spain
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Contact address: |
María Dolores Mayas-Torres Unit of Physiology University of Jaén Faculty of Experimental and Health Sciences Jaén E-23071 Spain jmmartos@ujaen.es |
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[Endocrinology] |
[Neuroscience] |
[Pharmacology] |
[Physiology] |
[Toxicology] |
Introduction. Pyroglutamyl aminopeptidase (pGluAP) is an omega peptidase which removes pyroglutamyl N-terminals residues from peptides and arylamidase derivatives. This activity is thought to be involved in the regulation of several physiological mechanisms on the central nervous system. pGluAP can modulate various susceptible endogenous substrates susch as thyrotropin-releasing hormone (TRH). It is well known that TRH plays an important role in the modulation of the behavioral changes induced by ethanol and others drugs. The aim of this work was to study the in vitro effects of ethanol (25, 50 and 100 mM) on the pGluAP activity and its ability for modulating the TRH. Material and Methods. pGluAP activity was measured in synaptosomes from cerebral cortex of mouse, using pyroglutamyl- -naphthylamide as substrate in basal and stimulated (K+ 25 mM) conditions, and in presence or absence of calcium on the buffer. Results. In basal conditions, ethanol produced an inhibition of the pGluAP activiy in presence or absence of calcium, this inhibition is not dose-related. However, the stimulation with K+ 25 mM did not produce a modification of pGluAP activity in presence of calcium, but produce an inhibition in absence of it. Depolarization in presence or absence of calcium and ethanol produced an inhibition of pGluAP activity, which changed in function of ethanol concentration. Conclusions. Ethanol modifies pGluAP activity in basal conditions by a mechanism independent of calcium, but the changes obtained from the stimulation with K+ may be a calcium-dependent mechanism. This variations of pGluAP activity induced by ethanol, and their effects on their endogenous substrates (specially TRH) may be responsible for the behavioral changes asociated to the alcoholism and mediated by TRH.
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[Endocrinology] |
[Neuroscience] |
[Pharmacology] |
[Physiology] |
[Toxicology] |
