[Mast cells in bone pathology].

The authors have endeavoured to determine the place occupied by mast cells in bone tissue from the mode of action on the bone of their secretion products (metachromatic granules, heparin, prostaglandins), from their proliferation in reaction to some bone diseases (secondary mastocytosis) and from the bone lesions associated with systemic mastocytosis. Metachromatic granules are capable of chelating calcium, and heparin and prostaglandins stimulate bone resorption. However, the role of mast cells in bone remodeling through these mechanisms has not yet been demonstrated.

[Heparin osteoporosis : histomorphometric analysis of bone biopsy. One case (author's transl)].

Following a 7-month treatment with heparin, a young pregnant woman with a history of multiple phlebites complicated by pulmonary infarction developed osteoporosis with multiple compression fractures of the vertebrae. Histomorphometric analysis of a transiliac bone biopsy showed severe osteoporosis with rarefaction of the spongy bone, considerable increase of osteoclasts and fall in osteoblasts. The cortex was not atrophic and was the seat of active reconstruction.