Effects Of Growth Factor, GH And Culture Mediums On Rabbit Articular Chondrocytes Cultured In Vitro

Objective:To explore the effects of transforming growth factor 1 (TGF-1), Insulin Like growth Factor- I (1GF-1), Growth Hormone (GH) and culture mediums on the proliferation and differentiation of rabbit articular chondrocytes. Methods:This study consists of two parts. In the first part, the primary articular chondrocytes of 3-month-old rabbit were harvested and cultured with F-12 and 1640 culture mediums supplemented with 15% newborn calf serum respectively. Then, the anchoring time of chondrocytes was observed; the quantity of cultured chondrocytes was detected by cell counts at the 1st, 2nd, 3rd, 4th, 5th, 6th, 7th, 14th and 21st days; glycosaminoglycans (GAG) was determined by Alcian Blue staining and quantified by colorimetry assay; while collagen was investigated using MASSON staining and compared with Morphometric analysis.In the second part, the 3rd passage chondrocytes were treated with IGF-1, TGF-1 and GH at different concentrations, as well as with the mixture of IGF-1 and GH respectively. The quantity of cultured chondrocytes was detected by MTT assay at the 7th day.GAG and collagen were determined with the same methods of the first part. Then, the effects of IGF-1, TGF- 1, GH on the dedifferentiation and redifferentiation of chondrocytes were observed.At last, the effects of 1640, F-12 culture mediums and TGF-1, IGF-1, GH, 1GF-GH mixture on the proliferation and matrix synthesis of rabbit articular chondrocytes were compared by Paired-Samples T Test, Chi-squared test and One-Way ANOVA respectively. Results:1 The proliferation speed and anchoring time of primary rabbit articular chondrocytes in 1640 medium were better than in F-12 medium. In the 3rd passages, the matrix synthesis of chondrocytes was more abundant in 1640 medium than in F-12 medium, while there was little difference of proliferation speed and anchoring time between two mediums.2 The optimal concentrations to enhance chondrocytes proliferation were : TGF-p, 40ng/ml, IGF-1 100ng/ml, GH 500ng/ml, the mixture of IGF-1 lOOng/ml + GH 500ng/ml, and the IGF-GH mixture could significantly increase the proliferation and matrix synthesis of chondrocytes.3 TGF-1, IGF-1 could maintain the chondrocytes phenotype and postponed the dedifferentiation process. It also showed that TCF- 1 could stimulate dedifferentiated chondrocytes to restore chondrocytes phenotype.Conclusions:1640 culture medium is more ideal for the culture of rabbit articular chondrocyte, it facilitate the survival and proliferation of primary articular chondrocytes.Growth factors of appropriate concentrations can significantlyincrease the chondrocytes proliferation and matrix synthesis, and maintain its phenotype. GH can promote the proliferation of articular chondrocytes cultured in vitro too, and it has synergistic action with 1GF-1.