Figure 1.

Collagen protein and mRNA expression in cultured rat growth plate chondrocytes. Isolated rat chondrocytes were cultured until confluency. (a) Protein expression for collagen I, II and X was studied in cultured chondrocytes with type-specific antibodies and using the alkaline-phosphatase-anti-alkaline-phosphatase method. Collagen type I was expressed in the majority of the cultured cells. Collagen II was strongly detected in chondrocytes of polygonal shape, representing more than 80% of the cultured cells. In cultured chondrocytes, no reactivity towards the collagen X antibody was observed. The antigens of the antibodies are indicated below the figures. (b) mRNA expression of the various collagen types. PCR analysis revealed expression of mRNA for collagen (Coll) I and collagen II and only marginal expression of collagen X mRNA.