Ecotoxic responses of MDA and antioxidant enzymes in testes of the frog Rana nigromaculata due to exposures to lead and cadmium Effects of Cadmium on oxidative stress and antioxidative ability in the Frog Rana nigromaculata under a long-term exposure Effects of Cadmium on oxidative stress and metallothionein of liver in frog Rana nigromaculata