Primary Study On The Early Effect-biomarkers Of Manganism

Objective:To explore the early effect biomarker of manganism. Method:Occupational manganese exposure subjects (male) were recruited as field study subjects (collected10ml venous blood, and stored in4℃refrigerator for further inspection);24SD rats were randomly divided into three groups, control group (n=8), low dosage group (LD group, n=8) and high dosage group (HD group, n=8). Manganese, Omg/kg、mg/kg、5mg/kg, was given by intraperitoneal injection five times one week, for four weeks according to the weights of the rats. After four weeks contamination, the rats were sacrificed by head cut, and blood and brain tissue were collected. The contents of manganese in blood and brain tissue were measured by AAS; RT-PCR was conducted to detect expression of PARK2expression levels in whole blood. Parkin contents in rats’brain tissue were determined by immunohistochemical technique. Result:Body weights decreased rapidly in manganese exposure group in the first three weeks. Average weights both in the high dosage group and low dosage group were lower than that in the control group. Increasing manganese exposure accompanied with decreasing body weight (P<0.05). The manganese level in high dosage group and low dosage group was higher than that in the control group (p<0.05). Immunohistochemical result showed Parkin existed in all the detected brain tissues although mainly in neuron cytoplasm. The Parkin content in high dosage group was lower than that in the low dosage group, which was lower than that in the control group; RT-PCR result showed PARK2expression levels decreased gradually as the increasing exposure manganese level(p<0.05); PARK2expression level in whole blood of manganese exposure worker was lower than that in the control group (p<0.05). Conclusion:Manganese exposure could cause the decrease of PARK2expression, which might be the mechanism of manganese neurotoxicity; PARK2gene expression in whole blood of manganese contaminated rats and professional exposure worker was consistent in the alteration trend. The alteration of PARK2expression in whole blood could provide alarming information for manganism. The alteration of PARK2expression might work as the early manganism biomarker.