STRONTIUM CAUSES OSTEOMALACIA IN CHRONIC-RENAL-FAILURE RATS

Background. We recently reported an association between increased bone strontium (Sr) levels and osteomalacia in dialysis patients. Methods. To delineate whether or not Sr acts as a causal factor in the develop ment of osteomalacia, we devised the following study: four groups of c hronic renal failure (CRF) rats were given Sr, aluminum (Al), both of these compounds or none of the elements (controls). Results. Administr ation of Sr and/or Al resulted in increased bone levels of the respect ive elements. Histological examination revealed impairment of minerali zation in the Sr group and to a lesser extent in the Al group as compa red to the control group. There was also a significant increase in ost eoid area in the Sr group, but not in the Al group. No differences in bone surface or erodic perimeter were noted between the various study groups. Histochemically, Sr could be localized in calcified bone, main ly in new bone close to the osteoid/calcification front, a critical si te of bone mineralization. Histochemical findings were confirmed by el ectron probe X-ray microanalysis. Conclusions. These findings indicate that Sr accumulation in chronic renal failure rats resulted in the de velopment of osteomalacic lesions, in contrast to the Al group where a dynamic bone disease was induced in the present set-up. Further studie s are required to define the mechanism by which way Sr causes osteomal acia in chronic renal failure rats.