PARATHYROID HORMONE SECRETION IN DISORDERS OF CALCIUM METABOLISM STUDIED BY MEANS OF EDTA

1974 ◽  
Vol 75 (2) ◽  
pp. 286-296 ◽  
Author(s):  
J. H. Lockefeer ◽  
W. H. L. Hackeng ◽  
J. C. Birkenhäger
Keyword(s):  
Parathyroid Hormone ◽  
Primary Hyperparathyroidism ◽  
Calcium Metabolism ◽  
Hormone Secretion ◽  
Parathyroid Tissue ◽  
Small Mass ◽  
Idiopathic Hypercalciuria ◽  
List Type ◽  
Immunoreactive Parathyroid Hormone ◽  
Pth Level

ABSTRACT In 22 of 28 cases of primary hyperparathyroidism (PHP) the rise in the serum immunoreactive parathyroid hormone (IRPTH or PTH) level observed in response to lowering of the serum calcium by EDTA, exceeded that obtained in 8 control subjects. In 5 of these 22 patients who were studied again after parathyroidectomy the supranormal response was abolished. Fifteen of these 22 hyper-responsive PHP patients had basal IRPTH levels not exceeding the highest level in the controls and that of other groups of patients investigated (idiopathic hypercalciuria, non-parathyroid hypercalcaemia, operated PHP). Fourteen of the 22 hyper-reactive patients with PHP did not show hypocalcaemia during the infusion of EDTA. The extent of the release of PTH elicited by EDTA in cases of PHP does not as yet allow a prediction of the amount of pathological parathyroid tissue present, although all the PHP patients showing a normal release of PTH had a relatively small mass of parathyroid tissue (up to about 1 g) subsequently removed. In 9 cases of nephrolithiasis (8 of whom had idiopathic hypercalciuria) and in 7 cases of non-parathyroid hypercalcaemia, a normal PTH release was found.

THE EFFECT OF CALCIUM AND DIBUTYRYL-cAMP ON THE SECRETION OF PARATHYROID HORMONE BY HUMAN PARATHYROID ADENOMAS IN ORGAN CULTURE

1977 ◽  
Vol 85 (3) ◽  
pp. 541-547 ◽  
Author(s):  
M. Dietel ◽  
G. Dorn ◽  
R. Montz ◽  
E. Altenähr
Keyword(s):  
Parathyroid Hormone ◽  
Primary Hyperparathyroidism ◽  
Organ Culture ◽  
Inverse Relationship ◽  
Calcium Concentration ◽  
Culture Medium ◽  
Hormone Secretion ◽  
Dibutyryl Camp ◽  
Parathyroid Adenomas ◽  
Immunoreactive Parathyroid Hormone

ABSTRACT The effect of different calcium concentrations as well as dibutyryl-cyclic adenosine 3′,5′-monophosphate (DB-cAMP) on the secretion of parathyroid hormone by human parathyroid adenomas taken from patients with primary hyperparathyroidism (pHPT) was studied in organ culture. Their influence on the release of hormone was determined. The tissue was incubated in culture medium for 4 h; the medium was changed hourly and analyzed for immunoreactive parathyroid hormone (PTH) by radioimmunoassay. The hormone secretion showed an inverse relationship to different calcium concentrations in the medium and could be stimulated independently of the calcium concentration by adding DB-cAMP. These results suggest that the examined parathyroid adenomas are sensitive to physiological stimuli.

Severe Primary Hyperparathyroidism in a Neonate With Two Hypercalcemic Parents: Management With Parathyroidectomy and Heterotopic Autotransplantation

PEDIATRICS ◽  
1986 ◽  
Vol 78 (2) ◽  
pp. 263-268
Author(s):  
Linda Cooper ◽  
Joseph Wertheimer ◽  
Raphael Levey ◽  
Edward Brown ◽  
Meryl Leboff ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Primary Hyperparathyroidism ◽  
Confounding Factor ◽  
Parathyroid Tissue ◽  
Normal Serum ◽  
Familial Hypocalciuric Hypercalcemia ◽  
Normal Range ◽  
Hormone Levels ◽  
Immunoreactive Parathyroid Hormone

A neonate with severe primary hyperparthyroidism was successfully managed by parathyroidectomy and heterotopic autotransplantation (one third of one gland of the infant was implanted in the forearm). In vitro studies of parathyroid tissue from the infant revealed a severe defect in parathyroid suppressibility. Postoperatively, the infant had modest hypercalcemia, normal serum immunoreactive parathyroid hormone levels, hypermagnesemia, and relative hypocalciuria. The parents were related and both had asymptomatic hypercalcemia with mean serum immunoreactive parathyroid hormone levels that were within the normal range. Similar to the findings in the infant postoperatively, relative hypocalciuria in the presence of hypercalcemia was found in the mother; in contrast, the father had hypercalciuria. The presumed dominantly transmitted hypercalcemia in this kindred is consistent with familial hypocalciuric hypercalcemia with a confounding factor of ethanol possibly accounting for the hypercalciuria in the father.

ENDOCRINE EFFECTS OF LITHIUM:

1978 ◽  
Vol 88 (3) ◽  
pp. 528-534 ◽  
Author(s):  
C. Christiansen ◽  
P. C. Baastrup ◽  
P. Lindgreen ◽  
I. Transbøl
Keyword(s):  
Parathyroid Hormone ◽  
Primary Hyperparathyroidism ◽  
Serum Calcium ◽  
Lithium Treatment ◽  
Serum Magnesium ◽  
Endocrine Effects ◽  
Manic Depressive ◽  
Depressive Patients ◽  
Immunoreactive Parathyroid Hormone

ABSTRACT Ninety-six manic-depressive patients were studied during long-term lithium treatment. Highly significant elevations were observed respecting the levels of serum immunoreactive parathyroid hormone (P < 0.001) as well as the protein-corrected levels of serum calcium (P < 0.001) and serum magnesium (P <0.001), thus indicating a state of 'primary' hyperparathyroidism. The patients as a group had normophosphataemia and normophosphatasia supporting the impression of a rather mild state of biochemical hyperparathyroidism.

Regulation of parathyroid hormone secretion by plasma calcium in aging rats

1991 ◽  
Vol 260 (2) ◽  
pp. E220-E225 ◽  
Author(s):  
J. Fox
Keyword(s):  
Parathyroid Hormone ◽  
Hormone Secretion ◽  
Fold Increase ◽  
Male Rats ◽  
Aged Rats ◽  
Adult Rats ◽  
Dihydroxyvitamin D3 ◽  
Set Point ◽  
Skeletal Resistance ◽  
Immunoreactive Parathyroid Hormone

Plasma immunoreactive parathyroid hormone (irPTH) levels increase with aging. This study determined 1) whether NH2-terminal irPTH secretory responses to induced hypocalcemia differ between adult (6-mo-old) and aged (24- to 26-mo-old) male rats and 2) whether a higher set point for irPTH release by Ca is responsible for the elevated irPTH levels with aging. Basal irPTH levels were 68% higher and 1,25-dihydroxyvitamin D3 levels were 44% lower in aged rats. An acutely induced, constant hypocalcemic stimulus [0.32 mM decrement in ionized Ca (Ca2+) for 2 h] was developed in catheterized conscious adult and aged rats by ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) infusion using the Ca clamp technique. The initial irPTH secretory response to acute hypocalcemia (5-10 min) was reduced in aged rats (1.9- vs. 3.1-fold increase), suggesting reduced hormone stores. However, higher sustained irPTH levels (30 min to 2 h) were maintained in aged rats, indicating increased irPTH synthesis and release. The EGTA infusion rate necessary to maintain constant hypocalcemia was less in aged rats, suggesting skeletal resistance to PTH. Slow EGTA and Ca infusions were used to determine irPTH secretion at plasma Ca2+ levels from 0.7 to 1.5 mM. In aged rats, irPTH levels were higher at all Ca2+ concentrations, but the set point for irPTH release by Ca2+ was the same as in adult rats. Thus the elevated irPTH secretion in aged rats is not caused by a change in the set point for irPTH release but does result in decreased irPTH stores.

scholarly journals A novel CASR variant in a family with familial hypocalciuric hypercalcaemia and primary hyperparathyroidism

2020 ◽  
Vol 2020 ◽  
Author(s):  
Satyanarayana V Sagi ◽  
Hareesh Joshi ◽  
Jamie Trotman ◽  
Terence Elsey ◽  
Ashwini Swamy ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Primary Hyperparathyroidism ◽  
Organ Damage ◽  
Urinary Calcium ◽  
Interesting Case ◽  
List Type ◽  
Loss Of Function ◽  
Clearance Ratio ◽  
Hormone Levels ◽  
Severe Hypercalcaemia

Summary Familial hypocalciuric hypercalcaemia (FHH) is a dominantly inherited, lifelong benign disorder characterised by asymptomatic hypercalcaemia, relative hypocalciuria and variable parathyroid hormone levels. It is caused by loss-of-function pathogenic variants in the calcium-sensing receptor (CASR) gene. Primary hyperparathyroidism (PHPT) is characterised by variable hypercalcaemia in the context of non-suppressed parathyroid hormone levels. Unlike patients with FHH, patients with severe hypercalcaemia due to PHPT are usually symptomatic and are at risk of end-organ damage affecting the kidneys, bone, heart, gastrointestinal system and CNS. Surgical resection of the offending parathyroid gland(s) is the treatment of choice for PHPT, while dietary adjustment and reassurance is the mainstay of management for patients with FHH. The occurrence of both FHH and primary hyperparathyroidism (PHPT) in the same patient has been described. We report an interesting case of FHH due to a novel CASR variant confirmed in a mother and her two daughters and the possible coexistence of FHH and PHPT in the mother, highlighting the challenges involved in diagnosis and management. Learning points: Familial hypocalciuric hypercalcaemia (FHH) and primary hyperparathyroidism (PHPT) can coexist in the same patient. Urinary calcium creatinine clearance ratio can play a role in distinguishing between PHPT and FHH. Genetic testing should be considered in managing patients with PHPT and FHH where the benefit may extend to the wider family. Family segregation studies can play an important role in the reclassification of variants of uncertain significance. Parathyroidectomy has no benefit in patients with FHH and therefore, it is important to exclude FHH prior to considering surgery. For patients with coexisting FHH and PHPT, parathyroidectomy will reduce the risk of complications from the severe hypercalcaemia associated with PHPT.

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 ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Primary Hyperparathyroidism ◽  
Secondary Hyperparathyroidism ◽  
Murine Model ◽  
Hormone Secretion ◽  
Suppressive Effect ◽  
Receptor Expression ◽  
Parathyroid Glands ◽  
Calcium Sensing Receptor ◽  
Calcium Sensing

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.

Non-autonomy of parathyroid hormone secretion in acute primary hyperparathyroidism

1992 ◽  
Vol 37 (6) ◽  
pp. 565-569
Author(s):  
Pinhas P. Schachter ◽  
Mark D. Christy ◽  
Itamar S. Avigad ◽  
Moshe Shabtay ◽  
George S. Leight
Keyword(s):  
Parathyroid Hormone ◽  
Primary Hyperparathyroidism ◽  
Hormone Secretion

Surgeon-Performed Ultrasound Improves Localization of Abnormal Parathyroid Glands

2005 ◽  
Vol 71 (7) ◽  
pp. 557-563 ◽  
Author(s):  
Carmen C. Solorzano ◽  
Theresa M. Lee ◽  
Marcela C. Ramirez ◽  
Denise M. Carneiro ◽  
George L. Irvin
Keyword(s):  
Parathyroid Hormone ◽  
Primary Hyperparathyroidism ◽  
Thyroid Tissue ◽  
Parathyroid Tissue ◽  
Initial Step ◽  
Multiglandular Disease ◽  
Venous Sampling ◽  
Sporadic Primary Hyperparathyroidism ◽  
Operative Findings ◽  
Abnormal Tissue

With a secure diagnosis of hyperparathyroidism, preoperative localization of abnormal glands is the initial step toward limited parathyroidectomy (LPX). We investigated whether ultrasonography in the hands of the surgeon (SUS) could improve the localization of abnormal parathyroids when sestamibi scans (MIBI) were negative or equivocal. One hundred eighty patients with sporadic primary hyperparathyroidism (SPHPT) underwent preoperative SUS and MIBI scans before LPX guided by intraoperative parathormone assay. When the sestamibi scans were negative, SUS was used to localize the parathyroid, distinguish parathyroid from thyroid tissue, and to guide the intraoperative jugular venous sampling for differential elevation of parathyroid hormone (PTH). Operative findings, intraoperative hormone dynamics, and postoperative calcium levels determined successful localization. MIBI was negative or equivocal in 36/180 (20%) patients: 1) showed no parathyroid gland in 22 patients, 2) suggested an incorrect location for the abnormal gland in 9, and 3) was insufficient in recognizing multiglandular disease in 5. In these 36 patients, the addition of SUS led to the successful identification of the abnormal tissue in 19/36 (53%). In the remaining 17 patients with negative/equivocal scans, the parathyroid could not be clearly visualized by SUS. In these patients, SUS facilitated LPX by aiding preoperative transcutaneous jugular venous sampling for differentially elevated PTH (n = 3) and identifying questionable thyroid nodule versus parathyroid tissue (n = 1). Overall, SUS was useful in 23/36 (67%) patients with nonlocalizing MIBI scans, thus improving the rate of localization from 80 per cent to 93 per cent ( P < 0.01). Surgeon-performed cervical ultrasonography improved the localization of abnormal parathyroids by MIBI scan, adding to the success of limited parathyroidectomy.

Post-parathyroidectomy restoration of normal calcium homeostasis in neonatal primary hyperparathyroidism

1984 ◽  
Vol 105 (3) ◽  
pp. 350-353 ◽  
Author(s):  
J. L. C. Ch'ng ◽  
A. Kaiser ◽  
J. Lynn ◽  
G. F. Joplin
Keyword(s):  
Primary Hyperparathyroidism ◽  
Calcium Homeostasis ◽  
Feedback Inhibition ◽  
Hormone Secretion ◽  
Parathyroid Tissue ◽  
Total Parathyroidectomy ◽  
Total Removal ◽  
Ionic Calcium ◽  
Ectopic Parathyroid ◽  
Normal Calcium

Abstract. Total parathyroidectomy is required to cure neonatal primary hyperparathyroidism (NPH) as any parathyroid remnant quickly becomes hyperplastic, causing recurrent hypercalcaemia. We present a patient with NPH who had total removal of his eutopic parathyroid glands but continued to have parathyroid hormone secretion from presumed ectopic parathyroid tissue. Hypercalcaemia initially recurred but normal calcium homeostasis was established as the child grew older. We postulate that the underlying defect in NPH is decreased sensitivity to the serum ionic calcium feedback inhibition at the parathyroid receptor level and that this sensitivity can improve with age.

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