Light and electron immunoperoxidase localization of minor disulfide-bonded collagens in fetal calf epiphyseal cartilage.

New minor disulfide-bonded collagens were recently described in cartilaginous tissues. The localization of these molecules in epiphyseal proper and growth plate cartilage of fetal calf has been studied using light and electron immunoperoxidase microscopy. The labeling was restricted to the pericellular region of the chondrocytes with an increasing intensity form the superficial to the inner zone of the epiphysis. At the ultrastructural level, the fine-non striated fibrils of the pericellular matrix were stained, demonstrating their collagenous nature. These minor collagenous chains are thus new components of the chondrocyte "exoskeleton" in which other molecules (proteoglycans, chondronectin, fibronectin and type V collagen) have been previously demonstrated.