The Effect Of 17β-Estradiol On The Cultured Adult Female Rabbit Articular Chondrocytes And Its Association With Nitro Monoxide

Objective: By incubation of chondrocytes with 17 P -Estradiol (?) of different concentrations and comparison of proliferated and energy metabolic status of chondrocytes, the present experiment was conducted to estimate the in vitro metabolic responses of cultured articular cartilage cells derived from adult female rabbit and investigate whether NO play a intermediate role in the process. The aims of the study were to assess the actions of estrogens in absence of other hormones, serum, or growth factors and to establish the pattern of the in vitro response of chondrocytes from the adult female rabbit. It may provided a new idea and reliable experimental evidence for treatment of OA and other cartilaginous diseases on the clinic. Materials and methods: E2 was purchased from Sigma Corporation. Chondrocytes were derived from female New Zealand rabbit aged 12 months, cultured in vitro monolayer in Ham's F-12 medium containing 10% fetal bovine serum(FBS). The chondrocyts of second generation were cultured and incubated with E2 at concentrations ranging between 10~12 and 10~3M for 24 or 48 hours. Using the corresponding reagent boxes, we detected respectively the content of hydroxyproline in the matrix, NO and NOS in the cultured medium, observed proliferated and energy metabolic status of chondrocytes by MTT method. Result: (1) From 10-12 to 10-8M, 176-estradiol had not significanteffect on synthesis of collagen of chondrocytes, each group compared with control group, P> 0.05; however, it exert a inhibited action on the proliferation and energy metabolism of chondrocytes. each group compared with control group, P< 0.01. (2) From 10'7to 10~6M, both synthesis of collagen and proliferation or energy metabolism of chondrocytes were inhibited, each group compared with control group, P < 0.01. (3) From 10'7to 10"3M, E2 can stimulate chondrocytes to synthesize more NOS and the subsequent NO production, each group compared with control group, P < 0.01; but without significant differentiation between groups, P> 0.05.Conclusion: A direct effect of E2 on in vitro cultured cartilage cell metabolism was demonstrated, and it showed a dose-dependent "inconsistent" effect on II collagen synthesis and the proliferation and energy metabolic status of chondrocytes. It demonstrated a distinct inhibitory influence on the energy metabolic status of chondrocytes by doses from 10-12M to 10-6M. however, it play a controversial role in the synthesis of II collagen in the matrix, because a ambiguous effect when added from 10-12 to 10-9M for E2;but slight inhibitive effect from 10-8 to 10-6M. NO perhaps involved in the metabolic process of chondrocyes by E2.