Incorporation of 3H-proline into hyaline articular cartilage. An autoradiographic study in rats with and without adjuvant-induced arthritis.

The incorporation of 3H-proline into the hyaline articular cartilage of rats with and without adjuvant-induced arthritis was investigated 1 h after the intravenous injection of radioactive proline. In the control animals, silver grains were present predominantly over the chondrocytes at all times; on the 28th day the intensity of labeling was notably reduced. In the animals with adjuvant disease reduced radioactivity was observed in the cartilage of the arthritic joints from the 14th experimental day onwards. At all times, however, silver grains occurred over the chondrocytes, including those in the pannus-covered cartilage and in cartilage sequesters. It is concluded from the investigations that the arthritic process accompanying the development of pannus reduces collagen synthesis and that the pannus tissue ingrows vital cartilage.