scholarly journals Relationship between parathyroid calcium-sensing receptor expression and potency of the calcimimetic, cinacalcet, in suppressing parathyroid hormone secretion in an in vivo murine model of primary hyperparathyroidism

2005 ◽  
Vol 153 (4) ◽  
pp. 587-594 ◽  
Author(s):  
Takehisa Kawata ◽  
Yasuo Imanishi ◽  
Keisuke Kobayashi ◽  
Takao Kenko ◽  
Michihito Wada ◽  
...  

Cinacalcet HCl, an allosteric modulator of the calcium-sensing receptor (CaR), has recently been approved for the treatment of secondary hyperparathyroidism in patients with chronic kidney disease on dialysis, due to its suppressive effect on parathyroid hormone (PTH) secretion. Although cinacalcet’s effects in patients with primary and secondary hyperparathyroidism have been reported, the crucial relationship between the effect of calcimimetics and CaR expression on the parathyroid glands requires better understanding. To investigate its suppressive effect on PTH secretion in primary hyperparathyroidism, in which hypercalcemia may already have stimulated considerable CaR activity, we investigated the effect of cinacalcet HCl on PTH-cyclin D1 transgenic mice (PC2 mice), a model of primary hyperparathyroidism with hypo-expression of CaR on their parathyroid glands. A single administration of 30 mg/kg body weight (BW) of cinacalcet HCl significantly suppressed serum calcium (Ca) levels 2 h after administration in 65- to 85-week-old PC2 mice with chronic biochemical hyperparathyroidism. The percentage reduction in serum PTH was significantly correlated with CaR hypo-expression in the parathyroid glands. In older PC2 mice (93–99 weeks old) with advanced hyperparathyroidism, serum Ca and PTH levels were not suppressed by 30 mg cinacalcet HCl/kg. However, serum Ca and PTH levels were significantly suppressed by 100 mg/kg of cinacalcet HCl, suggesting that higher doses of this compound could overcome severe hyperparathyroidism. To conclude, cinacalcet HCl demonstrated potency in a murine model of primary hyperparathyroidism in spite of any presumed endogenous CaR activation by hypercalcemia and hypo-expression of CaR in the parathyroid glands.

2005 ◽  
Vol 16 (7) ◽  
pp. 2190-2197 ◽  
Author(s):  
Sagrario Cañadillas ◽  
Antonio Canalejo ◽  
Rafael Santamaría ◽  
Maria E. Rodríguez ◽  
Jose C. Estepa ◽  
...  

Nephron ◽  
2000 ◽  
Vol 85 (4) ◽  
pp. 317-323 ◽  
Author(s):  
Shozo Yano ◽  
Toshitsugu Sugimoto ◽  
Michiko Kanzawa ◽  
Tatsuo Tsukamoto ◽  
Tetsuya Hattori ◽  
...  

Author(s):  
John Newell-Price ◽  
Alia Munir ◽  
Miguel Debono

Primary hyperparathyroidism is a disorder of bone mineralization and renal physiology due to excess parathyroid hormone secretion. Parathyroid hormone (PTH) is produced and released by the parathyroid chief cells, under regulation of the G- protein-coupled calcium-sensing receptor. Primary hyperparathyroidism occurs when there is a loss of the inhibitory feedback of PTH release by extracellular calcium. The rise in PTH levels is initially associated with a normal serum calcium, and then over time with hypercalcaemia. The most common cause of primary hyperparathyroidism is a benign solitary adenoma (80%). Other causes include multiple adenomas and hyperplasia. This chapter reviews the causes, clinical features, and management of primary hyperparathyroidism.


Endocrinology ◽  
2005 ◽  
Vol 146 (4) ◽  
pp. 2015-2022 ◽  
Author(s):  
Brian J. Arey ◽  
Ramakrishna Seethala ◽  
Zhengping Ma ◽  
Aberra Fura ◽  
Jennifer Morin ◽  
...  

2002 ◽  
Vol 17 (12) ◽  
pp. 2206-2213 ◽  
Author(s):  
Cynthia S. Ritter ◽  
Daniel R. Martin ◽  
Yan Lu ◽  
Eduardo Slatopolsky ◽  
Alex J. Brown

2017 ◽  
Author(s):  
Courtney J. Balentine ◽  
C Taylor Geraldson

Successful surgery of the parathyroid glands depends on a thorough knowledge of their anatomic and developmental relations. This knowledge is crucial for locating ectopic parathyroids or preventing injury to the recurrent laryngeal nerve. In addition, the surgeon should understand the physiology and function of these glands. Unlike other conditions a surgeon might treat, physiology, and not anatomy alone, often dictates the timing and course of parathyroid procedures. This surgeon-oriented, focused review covers the development, histology, anatomy, physiology, and pathophysiology of the parathyroid. Figures show the location and frequencies of ectopic upper and lower parathyroid glands, and regulation of calcium homeostasis. This review contains 2 highly rendered figures, and 16 references Key words: calcitonin; hypercalcemia; hyperparathyroidism; multiple endocrine neoplasia; parathyroid; parathyroid hormone; primary hyperparathyroidism; secondary hyperparathyroidism; tertiary hyperparathyroidism


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Patricia P. Centeno ◽  
Amanda Herberger ◽  
Hee-Chang Mun ◽  
Chialing Tu ◽  
Edward F. Nemeth ◽  
...  

Abstract Extracellular phosphate regulates its own renal excretion by eliciting concentration-dependent secretion of parathyroid hormone (PTH). However, the phosphate-sensing mechanism remains unknown and requires elucidation for understanding the aetiology of secondary hyperparathyroidism in chronic kidney disease (CKD). The calcium-sensing receptor (CaSR) is the main controller of PTH secretion and here we show that raising phosphate concentration within the pathophysiologic range for CKD significantly inhibits CaSR activity via non-competitive antagonism. Mutation of residue R62 in anion binding site-1 abolishes phosphate-induced inhibition of CaSR. Further, pathophysiologic phosphate concentrations elicit rapid and reversible increases in PTH secretion from freshly-isolated human parathyroid cells consistent with a receptor-mediated action. The same effect is seen in wild-type murine parathyroid glands, but not in CaSR knockout glands. By sensing moderate changes in extracellular phosphate concentration, the CaSR represents a phosphate sensor in the parathyroid gland, explaining the stimulatory effect of phosphate on PTH secretion.


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