Objective To analyze the correlation between the transcriptional expressions of Cu/Zn-superoxide dismutase (Cu/Zn-SOD) and glutathione peroxidase (GSH-Px)1 and their enzyme activities in peripheral blood of arsenic-exposed population from a coal-burning area, and to explore their effects on the development of liver injury in endemic arsenism caused by coal-burning.
Methods The arsenic exposure group consisted of 133 people exposed to arsenic (including 25 non-cases and 108 cases) who were selected from the area with endemic arsenism caused by coal-burning. The case group was divided into no obvious hepatopathy group (38 cases) and 2 hepatopathy groups (including 43 mild and 27 moderate-severe cases). Another 34 normal persons from nonarsenic polluted villages were taken as the control group. Peripheral blood samples were collected from all subjects. The mRNA expressions of Cu/Zn-SOD and GSH-Px1 were detected by real-time quantitative reverse transcription polymerase chain reaction (qPCR). The activities of SOD, Cu/Zn-SOD and GSH-Px were detected by chemical methods.
Results Compared with the control group, mRNA expressions of Cu/Zn-SOD and GSH-Px1 in the hepatopathy group were significantly higher (P < 0.05 or P < 0.01). Compared with the non-case group, Cu/Zn-SOD mRNA were significantly higher in the hepatopathy group (P < 0.05). There was no significant difference among case groups. Compared with the control group and the non-case group, activities of SOD, Cu/ZnSOD and GSH-Px decreased obviously in the hepatopathy group (P < 0.05 or P < 0.01). Compared with the no obvious hepatopathy group, activities of SOD and Cu/Zn-SOD significantly decreased in the mild hepatopathy group (P < 0.05), and activities of SOD, Cu/Zn-SOD and GSH-Px in the moderate-severe hepatopathy group significantly decreased (P < 0.05 or P < 0.01). Compared with the mild hepatopathy group, activities of SOD significantly decreased in the moderate-severe hepatopathy group (P < 0.05). Transcriptional expressions of Cu/Zn-SOD and GSH-Px1 were positively correlated with the degree of liver injury (P < 0.01); however, their activities were negatively correlated with the degree of liver injury (P < 0.01); and there were negative correlations between the transcriptional expressions and the activities of Cu/Zn-SOD and GSH-Px1.
Conclusion The transcriptional expressions of Cu/Zn-SOD and GSH-Px1 may respectively influence their enzyme activities in arsenism; and a lower level of such enzymes may participate in the development of arsenic liver injury.
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