Figure 2.

MMPIs and osteoclastic resorption of ⁴⁵Ca-prelabeled 17-day-old fetal mouse metatarsals in vitro. A: The fetal bone explants were incubated with various doses of marimastat (open circle), CH3921 (filled circle), CH5902 (open triangle) or vehicle (DMSO). B: MMPIs marimastat and CH5902 inhibit the invasion of osteoclast-precursors from the perichondrium into the calcified cartilage. Fetal bones were incubated with 10⁻⁶M marimastat, CH5902, or vehicle for 4 consecutive days and processed for paraffin embedding and TRAcP staining. 39 TRAcP-positive multinuclear cells were identified in calcified cartilage (ml), while in the marimastat- and CH5902-treated metatarsal TRAcP-positive cells resided in the perichondrium (p). CH3921 did not affect the invasion of the calcified cartilage by osteoclasts. Original magnification, ×200.