Small dosages of ionizing radiation as a risk factor of systemic osteoporosis

Biopsy specimens from the wing of the ilium were examined in 16 liquidators of the Chernobyl Atomic Power Station accident. A test for clonogenic stromal cells was performed long with quantitative analysis of osseous tissue parameters and the histomorphometric assessment of remodelling processes (resorption and osteogenesis). There was strong evidence for the fact that small dose ionizing radiation might lead to the development of at least 3 types of osseous tissue metabolic disturbances: osteoporosis of the cortical bone; that of the cortical and spongy bones (the mixed type) and abnormalities arbitrarily defined as osteosclerosis. It was found that resorption was simultaneously or even before suppressed in osteoporosis in the liquidators, whereas in other forms of osteoporosis, inhibited ostepgenesis triggerred rarefaction of the bones. The negative effect of ionizing radiation on stromal cells of the bone marrow was evident by the studies of the efficiency of cloning of osteoblast precursors. No dependence of the revealed changes on the dosage of ionizing radiation and the various pattern of metabolic disturbances in the osseous tissue under the action of the same dosages suggest that a premorbid background is of definite value in the development of abnormalities.