BACKGROUND/AIM Primary hyperparathyroidism (pHPT) is an endocrine disease with the third highest incidence of all endocrine disorders after diabetes mellitus and hyperthyroidism. pHPT is typically caused by a solitary parathyroid adenoma, less frequently by multiple parathyroid gland disease (MGD) and rarely by parathyroid carcinoma. Secondary hyperparatyroidism (sHPT) is a common complication ...

In mammals, parathyroid hormone (PTH) is a key regulator of extracellular calcium and inorganic phosphorus homeostasis. Although the parathyroid glands were thought to be the only source of PTH, extra-parathyroid PTH production in the thymus, which shares a common origin with parathyroids during organogenesis, has been proposed to provide an auxiliary source of PTH, resulting in a higher than e...

1,25-Dihydroxyvitamin D3 (1,25(OH)2D3 dramatically decreases parathyroid hormone (PTH) gene transcription. We have now studied the effect of 1,25(OH)2D3 on the 1,25(OH)2D receptor (VDR) in the parathyroid in vivo. Rats were injected with 1,25(OH)2D3 and the parathyroid-thyroid tissue analyzed for PTHmRNA and VDRmRNA. 1,25(OH)2D3 (50 and 100 pmol ip) decreased PTHmRNA at 6 h with a maximum at 48...

Calcitriol treatment is used to reduce parathyroid hormone levels in azotemic patients with secondary hyperparathyroidism (HPT). Whether long-term calcitriol administration reduces parathyroid gland size in patients with severe secondary hyperparathyroidism is not clear. The aim of the study was to evaluate in vitro the effect of calcitriol on parathyroid cell proliferation and apoptosis in nor...

Multiple Endocrine Neoplasia type 1 (MEN1) syndrome is a rare complex tumor-predisposing hereditary disorder, inherited in an autosomal dominant manner (OMIM 131100). MEN1 is characterized by tumors of the parathyroids, the neuroendocrine cells of the gastro-entero-pancreatic tract, and the anterior pituitary. The molecular mechanisms that control parathyroid tumorigenesis are still poorly unde...

OBJECTIVE Primary hyperparathyroidism (pHPT) is characterized by excessive production of parathyroid hormone (PTH) due to parathyroid adenomas while uremic secondary HPT (sHPT) is caused by parathyroid hyperplasia in response to renal failure. Active vitamin D, 1,25-dihydroxyvitamin D(3) (1,25-(OH)(2)D(3)), with the vitamin D receptor (VDR) is involved in regulation of the calcium homeostasis t...

BACKGROUND Parathyroid adenoma with cystic degeneration is a rare cause of primary hyperparathyroidism. The clinical and biochemical presentation may mimic parathyroid carcinoma. CASE PRESENTATION We report the case of a 55 year old lady, who had longstanding history of depression and acid peptic disease. Serum calcium eight months prior to presentation was slightly high, but she was never wo...

OBJECTIVE Thyroidectomy is the most common cause of hypocalcemia. Preservation of parathyroid glands in situ is essential in preventing this complication. The aims of our study were to review patients who underwent parathyroid gland autotransplantation during thyroidectomy, and to compare hypocalcemia rates in patients with and without autotransplantation. MATERIAL AND METHODS Parathyroid gla...

PURPOSE The aims of this study were to determine the incidence and evaluate the risk factors for hypocalcemia after total thyroidectomy and to investigate how many parathyroid glands should be preserved to prevent postoperative hypocalcemia. METHODS From March 2007 to February 2011, a retrospective review of 866 patients who underwent total thyroidectomy and node dissection for thyroid cancer...

We previously demonstrated that extracellular calcium regulates vitamin D receptor (VDR) expression by parathyroid cells. Since the calcimimetic R-568 potentiates the effects of calcium on the calcium-sensing receptor, it was hypothesized that administration of R-568 may result in increased VDR expression in parathyroid tissue. In vitro studies of the effect of R-568 on VDR mRNA and protein wer...