RESUMO
Objective To observe the toxic effects of subacute manganese exposure through drinking water on blood system in rats and offer the scientific data for understanding manganese toxicity mechanism.Methods Male SPF SD rats were randomly divided into control group,high-dose and low-dose Mn-exposed group,12 animals in each group.The two Mn-exposed groups were treated with Mn at doses of 0.5,5.0 g/L,through drinking water,for 60 consecutive days.After 60 days of treatment,haemoglobin (Hgb),red blood cells count(RBC),platelet count(PC),white blood cells count(WBC)and differential count(WBC-DC)were examined by blood routine test.The activity of alanine aminotransferase(ALT),aspartate aminotransferase(AST),alkaline phosphatase(ALP),cholinestarase(ChE),monoamine oxidase(MAO),superoxide dismutase(SOD),nitric oxide synthase(NOS)and the level of glutathione(GSH),maleicdialdehyde(MDA)were determined.Results No significant differences of body weigh,Hgb, RBC and WBC were found among the 3 groups.PC and neutrophil(N)percent of WBC were higher,eosinophil(E)percent of WBC was significant lower in high dose and low dose Mn-exposed groups compared with the control group.None of basophil(B)and monocyte(M)was found in 3 groups.Compared with the control group,the activity of ALT,AST,ALP,ChE,NOS and MDA level increased,SOD activity and GSH level decreased significantly in high dose and low dose Mn-exposed groups,and significant doseeffect relationships were seen in the above changes.Conclusion Long term manganese exposure may have some adverse effects on the blood system in rats.