[Physiological osteopenia: histomorphometric findings].
The construction of bone results from the collaborative work of functional constituents; destructive cells or osteoclasts, the activity of which induces that of other, constructive cells, the osteoblasts. During the whole period of growth, construction surpasses destruction. During the rest of life the destructive process predominates, whence a physiological osteopenia, which affects man as well as woman, but which accelerates in the latter during the postmenopausal years. The measurement of this physiological osteopenia by bone biopsy shows clearly that it is due to a simultaneous diminution of these two processes. Common osteoporosis, of early appearance, presents in 50% of cases as the chemical and biological expression of an acceleration of normal processes. 30% of them, on the contrary, are accompanied by an excess of destruction, whereas the rate of construction remains normal. In about 20% of cases it is the constructive phase which is depressed, destruction remains normal.
D000328:Adult; D000368:Aged; D001857:Bone Matrix / Q000503:physiopathology; D001862:Bone Resorption / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008593:Menopause; D008875:Middle Aged; D010006:Osteoblasts / Q000473:pathology*; D010010:Osteoclasts / Q000473:pathology*; D010024:Osteoporosis / Q000503:physiopathology
L'ostéopénie physiologique: données histomorphométriques.