COLLAGEN TYPE-X - A COMPONENT OF THE SURFACE OF NORMAL HUMAN, PIG, AND RAT ARTICULAR-CARTILAGE

Collagen type X, a protein generally associated with hypertrophic chon drocytes of avian and mammalian growth plate during endochondral growt h of long bones, has been previously shown to be present during disrup tion of normal metabolic status of articular cartilage during osteoath ritis. We have demonstrated that collagen type X is present as a compo nent of normal articular cartilage in adult human, growing pig and new -born rat. The protein was immunolocalized in these tissues at the sur face of the articular cartilage and for human tissue there was some st aining of chondrocytes adjacent to the 'tidemark' zone. The presence o f collagen type X was confirmed by isolating the protein from these ti ssues and its identification by SDS-PAGE and immunodetection with anti bodies specific for collagen type X. (C) 1996 academic Press, Inc.