Effect of the Interaction of Parathyroid Hormone and Cyclosporine A on Bone Mineral Metabolism in the Rat

摘要: Cyclosporine A (CsA) induces high turnover osteopenia in the rat and there is evidence for this humans. Recent studies suggest that increases parathyroid hormone (PTH) may be involved posttransplantation bone loss. However, human are difficult to interpret since transplant patients usually receive a cocktail of immunosuppressants have underlying disease. Our aim was try resolve influence absence or presence PTH on CsA-induced Male Sprague Dawley rats aged 7-9 months, either sham operated parathyroidectomized (PTX), were randomly divided into vehicle CsA groups. All PTX given oral calcium supplementation ad libitum. The groups: basal, sham/vehicle, sham/CsA, PTX/vehicle, PTX/CsA. Serial biochemistry performed 0, 14, 28 days after start experimental period; histomorphometry period. Statistical analysis consisted group comparisons factorial analyses. results showed alone produced consistent with previous studies. In animals an increase mass. also decreased osteoblast activity recruitment, serum 1,25OH2D levels. Serum levels osteocalcin (BGP) unaffected by PTX. combination (PTX/CsA) did not differ statistically from controls most histomorphometric parameters measured, exception reduced mineral apposition formation rates, reflecting effects BGP differ, but control. Explanations these (1) exert their via separate mechanisms, negating each other; (2) PTH, managed cause loss, thus essential loss; (3) profound accelerated loss normal requires PTH. These findings help explain discrepancies found clinical where occurs elevated