[Experimental observations of the quantitative changes of proteoglycan in homogenous cartilage graft in the guinea pig].

The present work was to study the quantitative change of proteoglycan (PG) in homogenous cartilage graft in the guinea pig. Histological, histochemical and biochemical studies were undertaken at different times after grafting. The results revealed that there was a marked reducing trend of matrix PG within four weeks after grafting. Four weeks afterwards all indexes except hexuronic acid restored slowly and approached the level of the control group. By the 20th week, the activity of neutromucopolysaccharide, hexosamine, acid-mucopolysaccharide and alkaline phosphatase restored to 73.6% -93.7% of the control group (P > 0.05). The changes probably were caused by immune reaction and operative trauma. PG in the cartilage matrix forms a barrier for the chondrocytes, protecting the host's immune system from contacting and reacting with the chondrocytes of the graft. Though the core protein of PG has antigenicity, it is surrounded by acidmucopolysaccharide that has no antigenicity. We concluded that it is very important to maintain a high level of PG in order to prolong the survival of a cartilage graft.