Oxidative stress and aminopeptidases in Parkinson's disease patients with and without treatment.
OBJECTIVE
Mitochondrial dysfunction, oxidative stress and protein metabolism impairment are the main molecular events underlying the pathogenesis of Parkinson'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 patients 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 patients. Nondenaturing electrophoresis and Western blot results confirmed these findings.


CONCLUSIONS
The plasma LPO and LAC levels were high in both PD groups, indicating that they are elevated at an early stage of PD and are not affected by anti-PD treatment. The higher AP activities in ntPD versus tPD patients suggest that anti-PD treatment may improve 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.
Duran
Raquel
R
Department of Physiology and Institute of Neurosciences, Centro de Investigaciones Biomedicas, University of Granada, Granada, Spain.
Barrero
Francisco J
FJ
Morales
Blas
B
Luna
Juan D
JD
Ramirez
Manuel
M
Vives
Francisco
F
D000368:Aged; D000626:Aminopeptidases / Q000097:blood*; D000978:Antiparkinson Agents / Q000627:therapeutic use*; D002230:Carbidopa / Q000627:therapeutic use; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007773:Lactates / Q000097:blood; D007980:Levodopa / Q000627:therapeutic use; D008054:Lipid Peroxides / Q000097:blood; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology*; D010300:Parkinson Disease / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology*
D000978:Antiparkinson Agents; D007773:Lactates; D008054:Lipid Peroxides; D008055:Lipids; D007980:Levodopa; D000626:Aminopeptidases; D002230:Carbidopa