Abstract:

【Objective】 To isolate and compare the small molecular weight proteins in liver and testes of rabbits challenged by cadmium to recognize the mechanism of sensitivity of testes against cadmium. 【Method】 Ten male Chinchilla rabbits at the age of 6-month-old were injected subcutaneously by cadmium at different doses, nine days later, the animals were killed, livers and testes of the rabbits were removed and iced at ―70℃. Livers and testes were minced and homogenized and ultracentrifugated, the supernatant of livers and testes were collected, respectively, and a part of supernatant were passed a column with Sephadex G-75 and the column was calculated by marker. The wash solution from column were fractioned, proteins in each tube were measured by ultraviolet scanning, and cadmium and zinc in tubes were measured by atomic absorption spectrophotometry. 【Result】 There was a peak of protein in liver supernatant induced by cadmium measured at 254nm. The molecular weight of the protein within the peak was 6.0-10.0 kD, and heat-stable, cysteine was rich, could not be extracted by alcohol, no aromatic amino acid in the protein. The ratio of Cd/Zn was 4.7:2. The components of this protein was much similar as metallothionein. However, there was no peak of testis supernatant measured at 254nm, and no similar protein in testis supernatant of animals dosed by cadmium. 【Conclusion】 The reason of male rabbit testes are sensitive to cadmium challenge is that tastes can not produce matallothionein which can against heavy metals from damage.

Key words: testicle, liver, cadmium, sensitivity, metallothionein