Fax +41 61 306 12 34 E-Mail karger@karger.ch www.karger.com Original Paper Neurodegenerative Dis 2011;8:109–116 DOI: 10.1159/000315404 Oxidative Stress and Aminopeptidases in Parkinson’s Disease Patients with and without Treatment Raquel Duran   a Francisco J. Barrero   c Blas Morales   c Juan D. Luna   b Manuel Ramirez   d Francisco Vives   a a  Department of Physiology and Institute of Neurosciences, Centro de Investigaciones Biomedicas (CIBM), University of Granada, b  Department of Statistics, Faculty of Medicine, University of Granada, and c  Movement Disorder Unit of San Cecilio University Hospital, Granada, and d  Unit of Physiology, Department of Health Sciences, University of Jaén, Jaén, Spain LPO and LAC levels were high in both PD groups, indicating that they are elevated at an early stage of PD and are not af- fected by anti-PD treatment. The higher AP activities in ntPD versus tPD patients suggest that anti-PD treatment may im- prove protein metabolism while not altering oxidative stress. A therapy directed to reduce oxidative stress and normalize AP activity may be useful in the treatment of PD. Copyright © 2010 S. Karger AG, Basel Introduction Parkinson’s disease (PD) is a progressive neurodegen- erative movement disorder pathologically characterized by the selective loss of dopaminergic (DA) cells in the substantia nigra pars compacta (SNPC) and the presence of cytoplasmic inclusions termed Lewy bodies. Clinically, the cardinal symptoms are bradykinesia, resting tremor, rigidity and postural instability. A number of patients also suffer from autonomic, cognitive and psychiatric disturbances [1]. PD is the second most common neuro- degenerative disease and its incidence increases with higher age, which is the main risk factor for the disease [2]. Although the mechanisms responsible for neurode- generation in PD are largely unknown, mitochondrial Key Words Parkinson’s disease  Oxidative stress  Protein metabolism, impairment Abstract Background/Objective: Mitochondrial dysfunction, oxida- tive stress and protein metabolism impairment are the main molecular events underlying the pathogenesis of Parkin- son’s disease (PD). However, only few studies have addressed the changes produced by these phenomena in the blood of PD patients. Our purpose was to compare oxidative stress between newly diagnosed PD patients (ntPD) and PD pa- tients under treatment (tPD). We also analyzed changes in plasma activity of several aminopeptidases (AP) involved in the metabolism of various active peptides. Methods: Plasma lipid peroxide (LPO) and lactate (LAC) concentrations were measured by colorimetric methods, and plasma AP activities were determined by fluorometric assay. Results: LPO and LAC concentrations were significantly elevated in ntPD and tPD patients versus controls, but there were no differences between the PD groups. Alanine-, cystine- and aspartate-AP activities were significantly lower in tPD versus ntPD pa- tients. Nondenaturing electrophoresis and Western blot re- sults confirmed these findings. Conclusions: The plasma Received: October 22, 2009 Accepted after revision: May 21, 2010 Published online: August 12, 2010 Diseases Prof. Francisco Vives Department of Physiology and Institute of Neurosciences, Faculty of Medicine, University of Granada, Avenida de Madrid 11 ES–18012 Granada (Spain) Tel. +34 95 824 3525, Fax +34 95 824 6179, E-Mail fvives  @  ugr.es © 2010 S. Karger AG, Basel 1660–2854/11/0083–0109$38.00/0 Accessible online at: www.karger.com/ndd