Cyclosporine A induced bone loss : densiometrical, biochemical and immunological evaluation / Perda ossea associada a ciclosporina A : avaliação densiometrica, bioquimica e imonologica

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

Several reports suggest that Cyclosporin A (CsA) causes increased bone turnover and remodeling with resorption exceeding formation, resulting in bone loss. The mechanism of CsA-induced bone loss is complex and can involve cellular bone markers and osteoblasts and osteoclasts products. CsA seems to have effects on nitric oxide (NO) production, which has a biphasic effect on osteoclastic bone resorption. The aim of the present study was to evaluate the effects of the CsA on bone by Bone Mineral Density (BMD), biochemical analysis (Total Alkaline Phosphatase - ALP and serum calcium) and to relate them with the expression of NO and Tumor necrosis factor alpha (TNFa.) by peritoneal macrophage of mice. Sixty male mice were distributed into 4 groups and CsA (Sandimmun Novartis) was injected subcutaneously in a daily dose of 50mg/kg body weight during the periods of 7, 14, 28 and 60 days (n=10), whereas control mice received saline solution (n=5). Blood samples were obtained by direct cardiac puncture. Serum calcium and total alkaline phosphatase levels were obtained. Macrophages were obtained trom the peritoneal cavities of treated and control mice 3 days after intraperitoneal administration of sodium thyoglycollate. Cells were incubated with lipopolysaccharide (LPS). After incubation, the culture supernatants were used for NO-and TNFa production assays. Digital radiographs of femurs were obtained with the use of a computerized imaging system, CDR R. Bone mineral density (BMD) measurements were made with the help of the software Photoshop 7,0 (Microsoft, 2003). The concentration of serum bone markers varied with the period of CsA administration. There was a significant decrease in the calcium levels after 28 days and ALP after 7 days. The BMD decreased significantly on distal epiphysis of femurs after 14 days and on proximal epiphysis after 60 days, in the mice submitted to CsA therapy. NO and TNF-a production had a significant increase in mice treated with CsA (7 and 14 days). Based on the results ofthe present study we confirmed that CsA induces bone loss in vivo. There was a synergism between the bone loss and the decrease of alkaline phosphatase, and calcium, and the increase ofNO and TNF-a

ASSUNTO(S)

bones ossos fator de necrose de tumor cyclosporin a interleucinas oxido nitrico ciclosporina interleukins tumor necrosis factor nitric oxide

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