Objective To investigate the influenceof insulin-like growth factor-I (IGF-I) on biological characteristics of articular chondrocytes cultured in vitro of rabbits. Methods Monolayer articular chondrocytes of 4week old rabbits were cultured in medium with IGF-I, at the concentrations of 3, 10, 30, 100, and300ng/ml. The DNA content in cells and glucuronic acid content in matrix were detected on the 2nd, 4th, 6th days after culture. Results The DNA content in cells and the glucuronic acid content in matrix in articular chondrocytes cultured in medium with IGF-I at concentrations of 3-300ng/ml were all significantly higher than those in control group (P＜0.01), which reached the peak at the concentrations of 30-100mg/ml on the 4th day. Conclusion IGF-I could obviously promote theproliferation of articular chondrocytes in vitro, and there exist time-dependent and dose-dependent effect.
ObjectiveTo explore the distribution and features of the optic cup stem cells in embryonic rat at tailbud stage.MethodsThe distribution of optic cup stem cells in optic cup tissue in 12.5-embryonic-day-old rats was observed by immunohistochemistry. The separated cells from optic cup were cultured with serum-free media, and immunofluorescence technique was used to detect the ability of hyperplasia of stem cells and expression of CHX10 antigen and specific antigens of mature retinal cells before and after differentiation.ResultsThe optic cup stem cells in embryonic rat at tailbud stage were mainly located at inner, outer, and marginal layer of optic cup. No expression of specifically marked protein of mature retinal cells was detected. The cells separated from optic cup had the ability of single-cell clone, positive expression of CHX10 and expression of several specific antigens of mature retinal cells after the inducement, including Thy1.1, glial fibrillary acidic protein (GFAP), protein kinase C (PKC) α, and rhodopsin.ConclusionOptic cup of 12.5-embryonic-day-old rats composes of undifferentiated cells, and the stem cells are mainly located in optic cup inner and marginal. High ability of hyperplasia of the optic cup stem cells cultured in vitro is found. The cells, which are retinal stem cells, can express several specifically marked proteins of mature retinal cells after inducement and differentiation.(Chin J Ocul Fundus Dis, 2005,21:159-162)