Pre-cultivation in suspension obtained chondrocyte-enriched cultures from articular-epiphyseal cartilage in fetal rats.

To establish a reliable chondrocyte culture system is valuable for investigating the phenotypic properties or the drug effects on chondrocytes. In this study, we established a chondrocyte-enriched culture system by pre-cultivating cells isolated from fetal rat articular and epiphyseal cartilage in suspension prior to cultivating in monolayer. Our results showed that the cultures with 5 days of preculture in liquid suspension produced the highest chondrocyte representative matrix of sulfated glycosaminoglycan compared to those with 1 or 3 days in suspension. We also found that PGE2 (10 and 100 nM) effects on DNA synthesis showed biphasically in 1 day-suspension chondrocyte cultures, similar to those of fibroblast cultures, while PGE2 (1-100 nM) revealed suppressive effects on DNA synthesis in 3 day-suspension chondrocyte cultures, similar to those of osteoblast cultures. However, PGE2 (0.1-100 nM) had no significant effects on the DNA synthesis of 5 days-suspension chondrocyte cultures. These results suggest that the monolayer chondrocyte culture following 5 days of suspension may be a reliable method to exclude the contaminated cells and obtain the chondrocyte-enriched cultures. In this study, we also found that 24-hour treatment of PGE1 (100-1000 nM), but not PGE2 or PGF2 alpha, revealed inhibitory effects on DNA synthesis in chondrocyte-enriched cultures. These phenomena may be as markers to check the characteristics of chondrocyte cultures derived from rat articular and epiphyseal cartilage, and also provide the information for further investigation about chondrocytic functions.