Oxidative DNA damage and oxidative stress in lead-exposed workers.
There are many discrepancies among the results of studies on the genotoxicity of lead. The aim of the study was to explore lead-induced DNA damage, including oxidative damage, in relation to oxidative stress intensity parameters and the antioxidant defense system in human leukocytes. The study population consisted of 100 male workers exposed to lead. According to the blood lead (PbB) levels, they were divided into the following three subgroups: a group with PbB of 20-35 μg/dL (low exposure to lead (LE) group), a group with a PbB of 35-50 µg/dL (medium exposure to lead (ME) group), and a group with a PbB of >50 μg/dL (high exposure to lead (HE) group). The control group consisted of 42 healthy males environmentally exposed to lead (PbB < 10 μg/dL). A comet assay was used to measure the DNA damage in leukocytes. We measured the activity of superoxide dismutase (SOD), catalase, glutathione reductase (GR), glucose-6-phosphate dehydrogenase (G6PD), and glutathione-S-transferase (GST) as well as the concentration of malondialdehyde (MDA), and the value of the total antioxidant capacity. The level of PbB was significantly higher in the examined subgroups than in the control group. The percentage of DNA in the tail was significantly higher in the LE, ME, and HE subgroups than in the control group by 10% ( p = 0.001), 15% ( p < 0.001), and 20% ( p < 0.001), respectively. The activity of GR was significantly lower in the LE and ME subgroups than in the control group by 25% ( p = 0.007) and 17% ( p = 0.028), respectively. The activity of G6PD was significantly lower in the ME subgroup by 25% ( p = 0.022), whereas the activity of GST was significantly higher in the HE subgroup by 101% ( p = 0.001) than in the control group. Similarly, the activity of SOD was significantly higher in the LE and ME subgroups by 48% ( p = 0.026) and 34% ( p = 0.002), respectively. The concentration of MDA was significantly higher in the LE, ME, and HE subgroups than in the control group by 43% ( p = 0.016), 57% ( p < 0.001), and 108% ( p < 0.001), respectively. Occupational lead exposure induces DNA damage, including oxidative damage, in human leukocytes. The increase in DNA damage was accompanied by an elevated intensity of oxidative stress.
1 Department of Biochemistry, School of Medicine with the Division of Dentistry in Zabrze, Medical University of Silesia, Katowice, Poland.
M
M
Dobrakowski
2 Department of Chemical Hazards and Genetic Toxicology, Institute of Occupational Medicine and Environmental Health in Sosnowiec, Sosnowiec, Poland.
N
N
Pawlas
1 Department of Biochemistry, School of Medicine with the Division of Dentistry in Zabrze, Medical University of Silesia, Katowice, Poland.
A
A
Kasperczyk
2 Department of Chemical Hazards and Genetic Toxicology, Institute of Occupational Medicine and Environmental Health in Sosnowiec, Sosnowiec, Poland.
A
A
Kozłowska
2 Department of Chemical Hazards and Genetic Toxicology, Institute of Occupational Medicine and Environmental Health in Sosnowiec, Sosnowiec, Poland.
E
E
Olewińska
1 Department of Biochemistry, School of Medicine with the Division of Dentistry in Zabrze, Medical University of Silesia, Katowice, Poland.
A
A
Machoń-Grecka
1 Department of Biochemistry, School of Medicine with the Division of Dentistry in Zabrze, Medical University of Silesia, Katowice, Poland.
S
S
Kasperczyk
D000328:Adult; D000395:Air Pollutants, Occupational / Q000097:blood / Q000633:toxicity*; D002374:Catalase / Q000097:blood; D020552:Comet Assay; D004249:DNA Damage; D005954:Glucosephosphate Dehydrogenase / Q000097:blood; D005980:Glutathione Reductase / Q000097:blood; D005982:Glutathione Transferase / Q000097:blood; D006801:Humans; D007854:Lead / Q000097:blood / Q000633:toxicity*; D007962:Leukocytes / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D008669:Metallurgy; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*; D018384:Oxidative Stress / Q000187:drug effects*; D011524:Protoporphyrins / Q000097:blood; D013482:Superoxide Dismutase / Q000097:blood; D055815:Young Adult
D000395:Air Pollutants, Occupational; D011524:Protoporphyrins; C017803:zinc protoporphyrin; D007854:Lead; D008315:Malondialdehyde; D005954:Glucosephosphate Dehydrogenase; D002374:Catalase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D005982:Glutathione Transferase
DNA damage; antioxidant defense system; lead poisoning; lipid peroxidation; oxidative stress