Immunofluorescence localization of type-M collagen in articular cartilage

Normal mammalian articular cartilage has been found to contain several collagenous peptide chains in addition to type-II collagen. We now report the distribution in adult pig cartilage of one of these new peptides, type-M collagen, using type-specific antibodies. Type M is primarily located in the pericellular environment of the cells in the deeper zones of the articular cartilage. The distribution is shown to be distinct from that of type-II collagen. This finding suggests that type-M collagen may play an important role in the metabolism of articular cartilage.