The Expression Of Interleukin-1, -6 And Collagen Type Ⅰ,Collagen Type Ⅱ MRNA In The Bone Of Ovariectomized Rats

Object: This paper addressed IL-1, IL-6, Collagen type I and Collagen type II mRNA expression in the tibias of ovariectomozed rats and revealed some relationships between osteoporosis and cytokines. Methods: An adult ovariectomized rat model was used in this study. The contents of serum Ca, P and AKP were tested. IL-1, IL-6, Collagen type I and Collagen type II mRNA expression and distribution were investigated by in situ hybridization respectively. Results: the contents of serum P and serum AKP of ovariectomized group were significantly higher than that of normal group. The number of bone marrow stromal cells which expressing IL-1 mRNA increased significantly after ovariectomized, so did the IL-6 mRNA in osteoblasts and Collagen type II mRNA in chondroncytes which located in epiphyseal plate. But the number of cells which expressing Collagen type I mRNA in epiphyseal plate and metaphysis bone trabecul'ae was decreased significantly in ovariectomized group than that of normal group. Conclusions: (1) The expression level of IL-1 and IL-6 mRNA increased in osteoporosis model may implied that IL-1 and IL-6 play important role in both osteoclasts formation and differentiation, and then induced active bone absorption. (2) With the level of estrogen decreasing, the transformation of hypertrophic chondroncytes to bone forming cells was retarded. This change may affect the synthesis of bone matrix protein and trigger the pathogenic procedure of osteoporosis.