Abstract: Objective: To explore the effect of age and origin on the proliferation and the chondrogenic differentiation capability of canine mesenchymal stem cells(MSCs) in vitro. Methods: MSCs isolated from bone marrows of the iliac bone and the shin bone in 4-month and 12-month canines, were cultured and induced into chondrocytes in vitro. The growth, purification, proliferation and chondrogenic differentiation abilities of MSCs in 4 groups were determined by using the clone forming rate and the MTT method. The GAG content and the positive cell rate of collagen Ⅱ were determined. Results: The proliferation and the chondrogenic differentiation abilities between MSCs isolated from iliac bones and shin bones were not statistically different in 4-month canines. In the 12month canine groups, MSCs showed a shorter primary culture time and a higher clone-forming unit rate from iliac bones than from shin bones, whereas the expression of GAG and collagen Ⅱ was not positively different. Both the proliferation and the chondrogenic differentiation abilities were higher in the 4-month groups than in the 12-month groups. Conclusion: The proliferation ability of MSCs from both sites is different in the 12-month canines, while the chondrogenic differentiation capability is not significantly different. The prolieration and the chondrogenic differentiation capabilities of the 4-month canines are higher than those of the 12-month canines.

Key words: Mesenchymal stem cells(MSCs), Canine, Age, Proliferation, Chondrogenic differentiation