ABSTRACT
[Objective] To observe the effect of stanozolol on proliferation and differentiation of cultured growth plate chondrocytes in vitro.[Methods] At 3 week of age,Sprague–Dawley rats received 2.5 mg/kg in slow-released GnRHa (triptorelin) which was repeated every 2 weeks for 2 times,at 7-week old.The tibial growth plate cartilage were aseptically dissected and tripsin and EDTA digested for 0.5 h,then collagenase digested for 3 h at 37 ℃.Chondrocytes were cultured in DMEM:F12 medium for 48 h,the cells were starved for 24 h in serum-free DMEM:F12 medium before stanozolol treatment.In dose-effect groups,chondrocytes were incubated in serum-free media in various concentrations of stanozolol for 48 h.In time-course groups,chondrocytes were incubated in serum-free media in various times of stanozolol (10-8 mol/L).immunohistochemical staining of collagen Ⅱ,Ⅹ,PCNA,and MTT were conducted.[Results] The results of MTT,PCNA,and typeⅡcollagen synthesization demonstrated stanozolol enhanced the proliferation of the chondrocytes,time-course studies had shown that the proliferation were maximally stimulated by stanozolol after 2 or 3 days of incubation and decreased again after longer periods of incubation.Stanozolol stimulated the proliferation of the chondrocytes dose-dependently at 10-11 mol/L and 10-8 mol/L,maximally stimulatory concentrations of Stanozolol was 10-9 ～ 10-8 mol/L,and decreased again after higher concentration of stanozolol.Stanozolol did not stimulated type X collagen synthesization from 10-11 mol/L ～ 10-8 mol/L,but experiments showed that type X collagen was already stimulated after incubation in Stanozolol (10-7 ～ 10-5 mol/L).Time-course studies had shown those typeⅩcollagen synthesizations were stimulated by stanozolol after 4 ～ 5 days of incubation.[Conclusion] Stanozolol enhances the proliferation of chondrocytes of pubertal female rat treated with GnRHa in vitro (time-course- dependent and concentration -dependent).