Effect of zinc treatments on cadmium exposed periparturient bovine lymphocytes in vitro on their proliferation and superoxide dismutase (SOD) expression

Abstract

This study was conducted to evaluate effect of cadmium (Cd) on lymphocyte proliferation and mRNA expression of Cu/Zn superoxide dismutase (SOD) and to determine whether zinc (Zn) treatment in Cd-exposed lymphocytes can modulate lymphocyte proliferation and SOD expression. Blood samples were collected from crossbred transition dairy cow at –30, –15, 0, 15 and 30 days of calving and evaluated for lymphocytes proliferation and SOD expression. Isolated lymphocytes were cultured with 10–3, 10–4, 10–5 and 10–6 molar (M) levels of Cd for 72 h. Adverse effect of transitional stress and Cd on lymphocyte proliferation and mRNA SOD expression was counteracted by 50, 55 and 60 micromolar (µM) Zn. Mitogenic response of lymphocyte and mRNA expression of SOD reduced as the days of parturition advanced. Lymphocyte proliferation and mRNA SOD expression showed negative correlation with Cd levels. Treatment of Zn in the Cd-exposed lymphocyte culture improved lymphocyte proliferation and relative abundance of SOD mRNA expression. In summary, Zn can ameliorate adverse effect of transitional stress and Cd on lymphocyte proliferation and SOD expression in dairy cows.