Association between subchronic and chronic lead exposure and levels of antioxidants and chemokines.
OBJECTIVE
This study aimed to compare the influence of lead on the non-enzymatic antioxidant defenses and the levels of chemokines in workers subchronically and chronically exposed to lead.


METHODS
The study population was divided into three groups. The first group consisted of male workers subchronically exposed to lead for 40 ± 3.2 days, while the second group included male workers chronically exposed to lead. The third group was a control group.


RESULTS
The levels of uric acid and bilirubin were significantly higher after a subchronic exposure to lead compared to the baseline by 22 and 35 %, respectively. Similarly, the values of total antioxidant capacity (TAC), total oxidant status (TOS), and oxidative stress index (OSI) increased by 15, 50, and 33 %, respectively. At the same time, the levels of thiol groups and albumin decreased by 5 and 8 %, respectively. Additionally, the levels of interleukin-8 (IL-8) and macrophage inflammatory protein-1β (MIP-1β) were significantly higher after a subchronic exposure to lead compared to the baseline by 34 and 20 %, respectively. Moreover, IL-8 level was significantly higher by 40 % in the group of workers chronically exposed to lead than in the control group, while the level of interferon gamma-induced protein-10 (IP-10) was significantly lower by 28 %.


CONCLUSIONS
Similar to chronic lead exposure, subchronic exposure to lead is associated with elevated blood levels of uric acid and bilirubin in humans. This probably results in increased TAC value despite thiol depletion. However, the compensatory activation of non-enzymatic antioxidant defenses seems to be insufficient to protect against lead-induced oxidative stress, which may be additively enhanced by the pro-inflammatory action of chemokines, especially IL-8.
Department of Biochemistry, School of Medicine with the Division of Dentistry, Medical University of Silesia, ul. Jordana 19, 41-808, Zabrze, Poland. michal.dobrakowski@poczta.fm.
Michał
M
Dobrakowski
Department of Biochemistry, School of Medicine with the Division of Dentistry, Medical University of Silesia, ul. Jordana 19, 41-808, Zabrze, Poland.
Aleksandra
A
Kasperczyk
Institute of Occupational Medicine and Environmental Health in Sosnowiec, ul. Kościelna 13, 41-200, Sosnowiec, Poland.
Natalia
N
Pawlas
Department of Biochemistry, School of Medicine with the Division of Dentistry, Medical University of Silesia, ul. Jordana 19, 41-808, Zabrze, Poland.
Ewa
E
Birkner
Department of Biochemistry, School of Medicine with the Division of Dentistry, Medical University of Silesia, ul. Jordana 19, 41-808, Zabrze, Poland.
Edyta
E
Hudziec
Department of Biochemistry, School of Medicine with the Division of Dentistry, Medical University of Silesia, ul. Jordana 19, 41-808, Zabrze, Poland.
Ewa
E
Chwalińska
Department of Biochemistry, School of Medicine with the Division of Dentistry, Medical University of Silesia, ul. Jordana 19, 41-808, Zabrze, Poland.
Sławomir
S
Kasperczyk
D000328:Adult; D000975:Antioxidants / Q000378:metabolism*; D001663:Bilirubin / Q000097:blood; D054407:Chemokine CCL4 / Q000097:blood; D054357:Chemokine CXCL10 / Q000097:blood; D018925:Chemokines / Q000097:blood*; D006801:Humans; D016209:Interleukin-8 / Q000097:blood; D007854:Lead; D007855:Lead Poisoning / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000097:blood*; D018384:Oxidative Stress; D012709:Serum Albumin / Q000032:analysis; D013438:Sulfhydryl Compounds / Q000097:blood; D014527:Uric Acid / Q000097:blood
D000975:Antioxidants; C114753:CXCL10 protein, human; C508606:CXCL8 protein, human; D054407:Chemokine CCL4; D054357:Chemokine CXCL10; D018925:Chemokines; D016209:Interleukin-8; D012709:Serum Albumin; D013438:Sulfhydryl Compounds; D014527:Uric Acid; D007854:Lead; D001663:Bilirubin
Chemokines; Chronic exposure to lead; Non-enzymatic antioxidants; Subchronic exposure to lead; Uric acid