Impairment of cell and plasma redox state in subjects professionally exposed to chromium.
BACKGROUND
Chromium (Cr) is widely used in chemical, tannery, building, and metal industries. More recently, it has been demonstrated that Cr induces oxidative stress in mouse brain. Nevertheless very few data exist on in vivo oxidative damage in humans exposed to Cr.


METHODS
Changes in antioxidant parameters both in plasma (acid ascorbic redox state and total antioxidant capacity) and in red blood cells (glutathione (GSH) redox state) of 40 subjects (age 37.65 +/- 7.46; M/F 20/20) professionally exposed to Cr who were recruited from metal, chemistry, and building industries were evaluated. We also evaluated the levels of lipoperoxidation (thiobarbituric acid-reactive material, TBA-RM) and thiol levels in plasma to assess the extent of oxidative stress state. To evaluate Cr exposure rate, we measured urinary-chromium (U-Cr) by an electrothermic atomization-atomic absorption spectrometry (ETA-AAS) method.


RESULTS
In this study, we found that Cr exposure induced a decrease both in GSH (P < 0.0005) and GSH/oxidized glutathione (GSSG) ratio (P < 0.0001) in red blood cells from workers with respect to control subjects. Furthermore, we also demonstrated a significant decrease of plasma acid ascorbic levels (45.7 +/- 14.9 vs. 53.5 +/- 16.5 micromol/L; P < 0.05) and in total plasma antioxidant capacity (1,126.3 +/- 212.2 vs. 1,266.9 +/- 207.8 micromol/L; P < 0.05) in subjects exposed to Cr. No difference was found with regard to TBA-RM and thiol levels.


CONCLUSIONS
This study demonstrated that in humans, an oxidative stress occurs for Cr exposures as low as those considered safe. This oxidative stress appears to be able to affect intracellular and plasmatic antioxidant defense.
De Mattia
Giancarlo
G
Department of Internal Medicine, University of Rome La Sapienza, Italy. giancarlo.demattia@uniroma1.it
Bravi
Maria Cristina
MC
Laurenti
Oriana
O
De Luca
Orietta
O
Palmeri
Alessandro
A
Sabatucci
Antonio
A
Mendico
Gino
G
Ghiselli
Andrea
A
D000328:Adult; D001205:Ascorbic Acid / Q000097:blood*; D002857:Chromium; D004912:Erythrocytes / Q000737:chemistry* / Q000378:metabolism; D005260:Female; D005978:Glutathione / Q000097:blood*; D006801:Humans; D015227:Lipid Peroxidation; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000502:physiology
D002857:Chromium; D005978:Glutathione; D001205:Ascorbic Acid