Poster
# 19
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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[Neuroscience] |
[Physiology] |
Introduction. It is well known the depressor effect of alcohol on several inhibitory nervous centres, in addition to its neurotoxic effect. This can be due to the inhibition that induces in the release of different type of neurotransmitters, and because it can increase the membrane fluidity and change the function of proteins that are inserted in the membrane. Several aminopeptidases (AP) have been described as enzymes that regulate the activity of peptidic neurotransmitters. In the present work, the activity of several aminopeptidases has been determined (AlaAP, ArgAP, CysAP, LeuAP and TyrAP) in synaptosomes obtained from the frontal cortex of mouse, under basal and K+-stimulated conditions, in presence of several doses of ethanol (25, 50 and 100 mM). The neurotoxic and metabolic effects of ethanol on synaptosomes has been investigated. Material and methods. The AP activities were determined using aminoacyl- -naphthylamides as substrates. The neurotoxic effects were analized by the determination of free radical generation, lipid peroxidation and oxidation of synaptosomal proteins. In addition, the bioenergetic behavior of synaptosomes was analized under the different experimental protocols. Results. In basal conditions, ethanol produces a dose-related inhibition of AlaAP activity. The rest of activities shows a two-phase behavior. In this way, depending on the concentration of ethanol, aminopeptidases are inhibited or stimulated. Depolarization with K+ 25 mM leads to a decrease of AlaAP and TyrAP activities but no in the rest. The presence of ethanol under stimulated conditions produces the inhibition of all the enzymatic activities, specially when the highest concentrations of ethanol are used. Under our experimental conditions, the presence of ethanol produces few signs of degeneration, although it can stimulate in a general way the energetic metabolism of synaptosomes. Conclusions. Ethanol modifies several aminopeptidase activities from synaptosomes of the frontal cortex of mouse, acting in different ways under basal or stimulated with K+ 25 mM conditions. These effects seem not to be related with degenerative events induced by ethanol. Therefore, must exist an specific effect of this substance on the neurotransmitter systems mediated by neuropeptides, modifying the enzymes that are responsibles of their degradation.
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[Neuroscience] |
[Physiology] |
