In vitro effect of copper treatments on mitogenic response and superoxide dismutase expression of lead exposed leukocytes from periparturient dairy cows

The aim of this study was to evaluate whether copper (Cu) treatment in lead (Pb)-exposed lymphocytes can modulate their proliferation and superoxide dismutase (SOD) expression. Blood samples were collected from advanced pregnant crossbred dairy cows at –30, –15, 0, 15, and 30 days of calving and evaluated for lymphocytes proliferation and mRNA expression of SOD. A fixed number of lymphocytes (2×106) were cultured for 72 h with 10–4, 10–5, and 10–6 molar (M) levels of Pb. Pb-exposed lymphocytes were treated with 30, 35 and 40 micro molar (µM) Cu. Mitogenic response of lymphocytes and mRNA expression of SOD reduced as the days of parturition advanced and were noted to be lowest at the day of calving. Reduced mitogenic response of lymphocytes and mRNA expression of SOD was reported in Pb-treated groups as compared to control. Addition of Cu in the Pb- exposed lymphocytes culture improved lymphocytes proliferation and relative mRNA SOD expression. Lymphocytes proliferation and relative mRNA SOD expression was reported highest in 40 µM Cu-treated groups. These results indicated that Cu can ameliorate the adverse effects of Pb on lymphocytes proliferation and SOD expression in periparturient dairy cows.