Impacts of combined supplementation with ascorbic acid and thiamine on certain biochemical and morphologic indexes of testes in mice treated by lead

OBJECTIVE: To investigate the impacts of the combined administration of ascorbic acid and thiamine on certain biochemical and morphologic indexes of testes in mice exposed to lead. METHOD: s 75 male mice were divided into control groups, groups received with 0.2% lead acetate and groups treated by the same lead acetate dose in combination with ascorbic acid and thiamine (subdivided into:low, middle and high-dose) ad libitum with 15 mice in each. 5 mice in each group were sacrificed at 2, 4 and 6 weeks respectively, and then testes were separated from mice. To evaluate the lead toxicity in testis, the levels of TGFbeta1 and Caspase-3 were detected by immunohistochemistry, apoptotic cell was determined by terminal deoxynucleotidyl transferase (TdT) mediated dUTP nick end labeling (TUNEL); DNA damage of germ cells was assessed by single cell gel electrophoresis (SCGE or Comet assay). RESULTS: The levels of TGFbeta1 and Caspase-3, apoptotic index were significantly higher in groups given by lead than those in control groups( P < 0.05 ). After intervention of low and middle-dose vitamins, DNA damage and the number of apoptotic cell in testis were obviously lower than those of groups exposed to lead( P < 0.05 ) . Also, the impaired tissues were markedly ameliorated under light microscope. Groups administrated with vitamins at the highest dose, however, promoted testicular cell apoptosis via elevated expression of TGFP, and Caspase-3, percentage of tail cell and tail length were reduced significantly. CONCLUSION: Thiamine and ascorbic acid could antagonize the action of certain toxicity of testes in mice treated by lead acetate.