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Calcimimetics maintain bone turnover in uremic rats despite the concomitant decrease in parathyroid hormone concentration
DOI:10.1016/j.kint.2018.12.015.png)
摘要
En 中文
Calcimimetics decrease parathyroid hormone (PTH) secretion in patients with secondary hyperparathyroidism. The decrease in PTH should cause a reduction in bone turnover; however, the direct effect of calcimimetics on bone cells, which express the calcium-sensing receptor (CaSR), has not been defined. In this study, we evaluated the direct bone effects of CaSR activation by a calcimimetic (AMG 641) in vitro and in vivo. To create a PTH clamp, total parathyroidectomy was performed in rats with and without uremia induced by 5/6 nephrectomy, followed by a continuous subcutaneous infusion of PTH. Animals were then treated with either the calcimimetic or vehicle. Calcimimetic administration increased osteoblast number and osteoid volume in normal rats under a PTH clamp. In uremic rats, the elevated PTH concentration led to reduced bone volume and increased bone turnover, and calcimimetic administration decreased plasma PTH. In uremic rats exposed to PTH at 6-fold the usual replacement dose, calcimimetic administration increased osteoblast number, osteoid surface, and bone formation. A 9-fold higher dose of PTH caused an increase in bone turnover that was not altered by the administration of calcimimetic. In an osteosarcoma cell line, the calcimimetic induced Erk1/2 phosphorylation and the expression of osteoblast genes. The addition of a calcilytic resulted in the opposite effect. Moreover, the calcimimetic promoted the osteogenic differentiation and mineralization of human bone marrow mesenchymal stem cells in vitro. Thus, calcimimetic administration has a direct anabolic effect on bone that counteracts the decrease in PTH levels.
Keyword:
bone
calcimimetic
CaSR
chronic kidney disease
mineral metabolism
parathyroid hormone
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期刊
IF:
12.6
论文数:
1.6W
被引数:
4.8W
机构
引用论文
Modulation of intracellular free Ca2+ concentration by IP3-sensitive and IP3-insensitive nonmitochondrial Ca2+ pools
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IF0
Etelcalcetide (AMG 416), a peptide agonist of the calcium-sensing receptor, preserved cortical bone structure and bone strength in subtotal nephrectomized rats with established secondary hyperparathyroidism
BONE
IF3.6
The effect of calcitriol, paricalcitol, and a calcimimetic on extraosseous calcifications in uremic rats
KIDNEY INTERNATIONAL
IF12.6

