Effects of Exposure to Hexavalent Chromium on the Level of 8-Hydroxydeoxyguanosine and the Activities of Superoxide Dismutase and 8-Hydroxyguanine Endonuclease in Rat Lung.
- Author:
Heon KIM
1
;
Hun Sik KIM
;
Rosa KIM
;
Hyeon Yeong KIM
;
Jae Hwang JEONG
Author Information
1. Department of Preventive Medicine, College of Medicine, Chungbuk National University, Industrial Chemical Research Center, Industrial Health Research Institute.
- Publication Type:Original Article
- Keywords:
chromium;
8-hydroxydeoxyguanosine;
8-hydroxyguanine endonuclease;
superoxide dismutase
- MeSH:
Animals;
Carcinogenesis;
Chromium*;
Cytochromes c;
Humans;
Lung*;
Male;
Potassium;
Rats*;
Rats, Sprague-Dawley;
Superoxide Dismutase*;
Superoxides*
- From:Korean Journal of Preventive Medicine
1999;32(1):101-107
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
OBJECTIVES: To determine the effects of exposure to hexavalent chromium, 93 male Sprague-Dawley rats were exposed to hexavalent chromium solution. METHODS: Rats were divided into 4 groups and exposed to 0.1 ml of 0 mM, 0.4 mM, 2.0 mM, and 10.0 mM potassium chromate in the first experiment, and to 0.1 ml of 0 mM, 20 mM, 40 mM, and 80 mM in the second for consecutive 3 days by tracheal instillation. Three and 10 rats were the controls for the first and the second experiments, respectively. Lung tissues were then removed to measure the 8-hydroxydeoxyguanosine (8-OH-dG) level using the HPLC-ECD method, superoxide dismutase (SOD) activity using the cytochrome C method, and 8-hydroxyguanine endonuclease activity using the oligonucleotide nicking assay. RESULTS: The results showed no significant linear relationship between chromium exposure level and 8-OH-dG level or 8-hydroxyguanine endonuclease activity. In the first experiment, 8-OH-dG level and 8-hydroxyguanine endonuclease activity increased in 0.4 mM group, and then decreased in 2.0 mM and 10.0 mM groups. The correlation coefficients between 8-OH-dG level and 8-hydroxyguanine endonuclease activity was statistically significant (P<0.01), and total SOD activity was elevated by chromium exposure in a dose-dependent manner (P<0.05). In contrast, there was no significant dose-response pattern or correlation in the second experiment. CONCLUSIONS: Based on the fact that there was no linear relationship between chromium dose and 8-OH-dG level or activity of the repair enzyme, it seems unlikely that 8-OH-dG formation is the major mechanism of chromium carcinogenesis.
