Histological analysis of chondrons isolated from age-related normal rabbit knee / 中华骨科杂志

ABSTRACT

Objective To explore the histological properties of isolated chondrons and chondrocytes from rabbit knee cartilage,and to determine if these properties vary with age.Methods Three groups of rabbit knees were evaluated according to different age(1) young (2 months,n=10);(2) adult (8 months,n=10);and (3) old (31 months,n=10).The cartilage structure,proteoglycan,collagen-2,and collagen-6 content were determined by light microscopic using hematoxylin-eosin (HE),Toluidine Blue,and col-2,6 staining.The chondrons were enzymatically isolated using 0.3 g/L dispase and 0.2 g/L collagenase-2 by shaking for 3 hours.The morphology and composition of isolated chondrons were observed by HE and collagen-6 immunostaining staining after overnight coverslip monolayer culture under a microscopy.Results The chondrocytes became sparser and the total content of proteoglycans and collagen-2 were decreased in the articular cartilage with age.Compared to the chondrocytes,the surrounding rim or capsule was more obvious in the isolated chondrons,and they exhibited obvious differences in shape.The cells within one cluster from different age groups were similar to the morphology observed in cartilage in situ.The adult and old chondrons generally possessed a thicker pericellular matrix with more enclosed cells,and the chondrons contained more cells can reach 47％.Conclusion These findings further suggest that the properties of the chondrons and pericellular matrix have an important influence on the biomechanical microenvironment of the knee joint cartilage degeneration that occurs with age.