Cytochemical localization of tartratemediate, and deep stages characterized by differences in resistant acid phosphatase (TRAP), tartrate-sensitive cartilage surrounding the canal (Cole and Wezeman, acid phosphatases (TSAP), alkaline phosphatase, and 1985). Superficial Canals terminate in uncalcified matrix nonspecific esterase was used to characterize perivascontaining nonhypertrophic chondrocytes; intermediate cular cells within cartilage canals.
the distal femoral canals terminate in uncalcified matrix containing hypertrophic chondrocytes; and deep canals terminate in epiphyses Of 5-to 7-day-01d mice, three stages Of calcified matrix. At each developmental stage, perivasdevelopment can be distinguished, and at each develcular cells with characteristics of degradative cells are opmental stage different perivascular cells were present present adjacent to the matrix surrounding the canal. with moWholo!&al characteristics of degradative cells-In the superficial canal, cells resembling macrophages Vacuolated cells resembling macrophages, fibroblastic with large vacuoles containing SLS (segment-long-spaccells, and chondroclasts were present adjacent to the ing) collagen fragments contact the collagenous portion matrix in superficial, intermediate, and deep canals, of the uncalcified matrix. In the intermediate canal, respectively. In order to characterize these perivascular enlarged fibroblastic cells with dense bodies resembling cells cytochemically, nonspecific esterase and TSH lysosomes and phagolysosomes form an intimate contact staining was used to identify macrophages, alkaline with the hypertrophic matrix, and in the deep canal, chondroclasts with ruMed borders and clear zones conphosphatase staining was used to identify fibroblastic tact the calcified matrix. cells, and TRAP staining was used to identify chondro-At other sites of cartilage matrix degradation, cells clasts* There were no present in the at epiphyseal cartilage prior to the development of the sparsely stained osteoblast-like cells, and unstained cells secondary center of ossification and are thought to form by the degradative activity of perivascular cells that accompany blood vessels within the canals. In the mouse, canal development can be divided into superficial, inter-localized in chondroclasts at the tips Of deep Canals but of acid phosphatase to inhibition by tartrate. Macrowas not confined exclusively to chondroclasts. Except phages can be distinguished by the presence of a tar-