Stereological studies on the epiphyseal growth plate with special reference to the distribution of matrix vesicles

Abstract

The matrix vesicles in growth cartilage are considered to play an important role in the mineralization process and it has been claimed that the distribution of these vesicles corresponds to the pattern of subsequent apatite deposition. Employing modern stereological techniques the present investigation showed a different distribution pattern from that previously described in the literature, the highest volume density of matrix vesicles being found in the resting zone and the lowest in the zone of calcification. The volume—density differences are explained by differences in the number of vesicles between zones. The variation in mean caliper diameter was small. The possible biological significance of these findings is discussed in relation to the proposed theories on matrix vesicle origin. Our findings seem to support the view that most of the matrix vesicles are formed from degenerating chondrocytes, although the possible existence of small subpopulations of matrix vesicles of more specialized origin cannot be rejected.