Abstract
Alkaline phosphatase (ALPase) activity was examined and compared by light and transmission electron microscopy in the rabbit lamellar bone in association with experimentally induced osteomyelitis. Staphylococcus aureus was injected into the proximal tibia of the young rabbit (Dekel and Francis, 1981). Its metaphysis portion was taken out 0, 2, 4, 6, and 10 weeks after injection. Specimens were prefixed, demineralized with EGTA, sectioned, then incubated for the demonstration of ALPase activity employing the lead citrate method (Mayahara et al. 1967). Osteomyelitis developed already 2 weeks after Staphylococcus injection. ALPase activity was observed manifestly in osteoblasts, and diffusely in the interce1lar matrix of the normal control. By electron microscopy, activity was localized primarily in the plasma membrane of the osteoblasts and the matrical collagen fibers. In osteoblasts taken out 2 weeks after the injection, intensely positive activity tended to be restricted to the plasma membrane facing the bone marrow. In osteomyelitic bony tissue, osteoblasts locating at the border between the bone lamella and the bone marrow often revealed a polarity in terms of the distribution pattern of ALPase activity.
