ABSTRACT
Objective: To investigate the effect of zinc sulfate and zinc methionine on growth and their possible regulating mechanism in mice. Method: Ninety male KM mice were randomly divided into three groups. The control group was fed on basal diet containing zinc of 11. 67 mg/kg 10d. The ZnSO4 group and Zn-Met group were fed on the diets supplemented with ZnSO4 or Zn-Met at 30 mg/kg(on the basis of Zn) for 10 d. Initial and final body weight,serum zinc concentration, growth hormone (GH),the levels of growth hormone receptor (GHR) and insulin like growth factor 1 (IGF-1) mRNA were determined. Results: Both ZnSO4 and Zn-Met enhanced body weight and serum zinc concentration of mice,Zn-Met more effectively than ZnSO4 for body weight . Both forms of zinc had no effect on GH and the expression of GHR mRNA , but both up-regulated the expression of IGF-1 mRNA. As compared to ZnSO4, Zn-Met enhanced the level of IGF-1 mRNA significantly. Conclusion: Both ZnSO4 and Zn-Met had no effect on GH and the expression of GHR Mrna,but enhanced the expression of IGF-1 mRNA. Zn-Met enhanced the body weight gain and up-regulated IGF-1 mRNA expression more effectively than ZnSO4.