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Parenteral pamidronate prevents thyroid hormone‐induced bone loss in rats
Author(s) -
Rosen Harold N.,
Sullivan E. Kelly,
Middlebrooks V. Leah,
Zeind Adib John,
Gundberg Caren,
DresnerPollak Rivka,
Maitland Lauri A.,
Hock Janet M.,
Moses Alan C.,
Greenspan Susan L.
Publication year - 1993
Publication title -
journal of bone and mineral research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.882
H-Index - 241
eISSN - 1523-4681
pISSN - 0884-0431
DOI - 10.1002/jbmr.5650081014
Subject(s) - endocrinology , medicine , osteocalcin , alkaline phosphatase , bone mineral , triiodothyronine , thyroid , placebo , bone remodeling , hormone , femur , chemistry , osteoporosis , surgery , pathology , biochemistry , alternative medicine , enzyme
Pamidronate (APD) is a bisphosphonate that prevents bone loss from a variety of causes. We studied the role of APD in preventing thyroid hormone‐induced bone loss. A total of 32 rats were assigned to one of four treatment groups: (1) −APD/triiodothyronine (−T 3 ), (2) −APD/+T 3 , (3) +APD/−T 3 , or (4) +APD/+T 3 . In the first of two studies, the rats received APD for the first week and T 3 for the second week, and then their blood was analyzed for alkaline phosphatase and osteocalcin. Alkaline phosphatase and osteocalcin were significantly higher ( p < 0.05) in hyperthyroid rats (−APD/+T 3 , 3.9 ± 0.25 μcat/liter and 23 ± 1.6 nM, respectively) than in control animals (2.53 ± 0.28 μkat/liter and 18.3 ± 1.4 nM, respectively). Hyperthyroid rats pretreated with APD (+APD/+T 3 ) had levels of alkaline phosphatase and osteocalcin no different from controls. In a second study, rats were divided into the same four groups, except they received APD/placebo and T 3 /placebo concomitantly for 3 weeks. At the end of the study, bone mineral density (BMD) of the femur, spine, and whole body was measured by dual‐energy x‐ray absorptiometry, and the calcium content of the femora was measured directly. In hyperthyroid rats (−APD/+T 3 ) BMD was significantly lower than in controls in the spine (0.201 ± 0.004 versus 0.214 ± 0.002 g/cm 2 , p < 0.05) and femur (0.204 ± 0.003 versus 0.218 ± 0.002, p < 0.05). In hyperthyroid rats pretreated with APD (+APD/+T 3 ) BMD of the spine, femur, and total body was significantly higher than in controls ( p < 0.001). Similar differences among groups were seen in femur calcium content. We conclude that hyperthyroid rats have an increased rate of bone turnover and bone loss that can be prevented by coadministration of a bisphosphonate.