Figure 1. Neutral metalloproteinase (MMP) and collagenase content of growth plate cartilage from normal and vitamin D/phosphate-deficient (-VDP) rats. At the animals' death, the proximal tibial growth plate cartilage was removed, and neutral MMP and collagenase were extracted and then assayed on aggrecan and type 1 collagen substrates. All values are the mean ± SEM in enzyme units/gram wet weight tissue for n 7 samples. *P < 0.05, normal vs. –VDP.