Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0221002 (primary hyperparathyroidism)
 4,921 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chronic administration of 1,25(OH)2D or PTH increases the set point at which plasma bicarbonate concentration is regulated by the kidney and thereby maintains metabolic alkalosis in a variety of species. The renal mechanism(s) responsible for the chronic acid excretory response to 1,25(OH)2D and PTH administration have not been defined, but indirect evidence suggests effects on distal nephron segments. With either hormone in dogs, but not in rats, metabolic alkalosis is generated in part by extrarenal mechanisms. Contrary to the variable finding of hyperchloremic acidosis in human primary hyperparathyroidism, a steady state of mild metabolic alkalosis of renal origin is achieved in normal human subjects infused chronically with PTH. The multiple potential mechanisms responsible for this discrepancy will require careful consideration in future investigations. The acute and chronic effects of plasma calcium concentration on both renal and extrarenal acid-base homeostasis are incompletely understood and require extensive further investigation. Studies in rats have suggested that phosphate depletion results in important counterbalancing renal acidosis and extrarenal alkalosis-producing effects. Chronic hypophosphaturia in the absence of appreciable hypophosphatemia can also result in impaired renal acidification by virtue of phosphate's property as a luminal buffer.
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PMID:Effects and interrelationships of PTH, Ca2+, vitamin D, and Pi in acid-base homeostasis. 298 44

The hypothesis that chronic metabolic acidosis encountered in some patients with primary hyperparathyroidism is due to inhibition of proximal HCO3 reabsorption has recently been challenged. Indeed, this action of parathyroid hormone (PTH) has only been observed in acute studies, whereas in animal models of chronic hyperparathyroidism a metabolic alkalosis has been induced, probably owing to the release of alkaline salts from bone tissue, and to the stimulation of tubular acid secretion by hypercalcaemia. Studies were, therefore, performed to determine the effect of PTH on the renal handling of HCO3 in an animal model in which changes in plasma calcium and phosphate, and nephrocalcinosis, all known to affect tubular acidification, did not occur. Thyroparathyroidectomized (TPTX) rats were infused with synthetic bovine hormone fragment bPTH 1-34 via Alzet minipumps at the rate of 0.7 U h-1 to simulate normal endogenous production of PTH (group I) and at the three-fold higher rate of 2.1 U h-1 (group II). In order to prevent changes in serum calcium and phosphate, and nephrocalcinosis, animals of group II were fed a Ca- and P-free diet prior to TPTX (compared with a regular diet for group I) and both groups were treated with dichloromethylene-diphosphonate (Cl2MDP, 10 mg kg-1 day-1) and a Ca-free diet during PTH infusion. During the course of PTH infusion both groups of animals had stable and normal levels of plasma calcium and phosphate.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Parathyroid hormone directly inhibits tubular reabsorption of bicarbonate in normocalcaemic rats with chronic hyperparathyroidism. 312 45

The chronic renal and systemic acid-base effects of hyperparathyroidism in humans remain controversial and unresolved. The present studies evaluated the acid-base response of normal human subjects to a 13-day intravenous infusion of synthetic b(1-34) PTH sufficient to result in sustained hypercalcemia and hypophosphatemia. The acid-base response was biphasic: an initial transient renal acidosis developed on the first day of PTH infusion, followed by a prompt increase in net acid excretion and plasma [HCO3-] of sufficient magnitude to result in a steady state of mild metabolic alkalosis. The results indicate that: 1) sustained, continuous, experimentally produced hyperparathyroidism results in a steady state of mild metabolic alkalosis; 2) the alkalosis is both generated and maintained, at least in part, by renal mechanisms; and 3) reported renal acidosis in sustained clinical conditions of primary hyperparathyroidism is not attributable to either direct or indirect effects of PTH excess when present for a 2-week period, an interval sufficient to re-establish a new steady state of renal and systemic acid-base equilibrium.
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PMID:Acid-base homeostasis during chronic PTH excess in humans. 383 29

In both normal volunteers and in patients with primary hyperparathyroidism, the induction of a metabolic alkalosis by infusion of sodium bicarbonate results in a decrease in serum calcium ion and in an increase of circulating parathyroid hormone concentrations. Bicarbonate infusion may serve in man as a new provocative test for release of parathyroid hormone. Furthermore, we speculate that the metabolic alkalosis which is found at times in patients with the Zollinger-Ellison syndrome and severe peptic ulcer disease may result in parathyroid gland stimulation.
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PMID:Ulcer disease, metabolic alkalosis and hyperparathyroidism: A mechanism of interrelationship? 441 67

A study is reported of the estimation of plasma chloride concentration and acid-base status in the differentiation of primary hyperparathyroidism from all other causes of hypercalcaemia. In the two groups of patients studied, all of whom had hypercalcaemia, there was complete separation between the two groups on the basis of plasma chloride concentration and acid-base status. In 16 patients with primary hyperparathyroidism the increase in plasma chloride concentration and associated metabolic acidosis could have been accounted for by the known renal tubular effects of parathyroid hormone. In 13 patients with hypercalcaemia due to various other causes the decrease in plasma chloride concentration and associated metabolic alkalosis could be accounted for either by the known effects of an excess of calcium-ion on the renal tubules, or perhaps by suppression of endogenous parathyroid hormone secretion. In patients with hypercalcaemia and hypophosphataemia of ;pseudohyperparathyroidism' associated with non-endocrine tumours it is postulated that the low plasma chloride concentrations and metabolic alkalosis found in these patients were due either to a differing biological activity of the parathyroid-hormone-like polypeptide secreted by the tumour cells, or possibly to simultaneous secretion by these cells of an ACTH-like polypeptide.
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PMID:Value of plasma chloride concentration and acid-base status in the differential diagnosis of hyperparathyroidism from other causes of hypercalcaemia. 557 36

The milk-alkali syndrome became rare with the advent of modern ulcer therapy with nonabsorbable antacids, histamine2 blockers, and sucralfate. An increased frequency of this syndrome seems likely with the growing popularity of the use of calcium carbonate as an antacid or as calcium supplementation to prevent osteoporosis. We treated five patients who had six episodes of the milk-alkali syndrome; four of these cases were diagnosed between 1990 and 1992. All patients were ingesting massive quantities of calcium and absorbable alkali and were unaware of the toxic effects of these compounds. All patients presented with the triad of hypercalcemia, metabolic alkalosis, and renal failure. All metabolic abnormalities were corrected, and renal function improved with appropriate supportive measures and cessation of calcium and alkali ingestion. In two patients, the renal failure was so severe that dialysis was necessary. In four patients, either the serum amino-terminal parathyroid hormone or 1,25-dihydroxycholecalciferol levels were appropriately decreased in response to hypercalcemia. The serum carboxy-terminal parathyroid hormone levels were increased because of renal failure. Since both physicians and patients are often unaware of the calcium and alkali content of many nonprescription medicines, the diagnosis of the milk-alkali syndrome, a reversible cause of renal failure, can be missed if a detailed history of such intake is not elicited. Measurement of the serum amino-terminal parathyroid hormone and 1,25-dihydroxycholecalciferol levels may help differentiate milk-alkali syndrome from primary hyperparathyroidism.
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PMID:The milk-alkali syndrome. A reversible form of acute renal failure. 848 Oct 62

Milk-alkali syndrome was once considered to be of historic interest and a rare cause of hypercalcemia. Currently, it should be an important consideration in the differential diagnosis of hypercalcemia, after malignancies and primary hyperparathyroidism. The resurgence is in part due to the easy availability of over the counter (OTC) calcium preparations. We describe a 50-year-old man who presented with severe hypercalcemia on two occasions associated with renal failure and metabolic alkalosis. Extensive investigations during the first admission failed to unravel a specific cause of hypercalcemia but a thorough history during his subsequent admission helped to confirm the diagnosis of milk-alkali syndrome.
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PMID:A hidden history of heartburn: The milk-alkali syndrome. 2145 29

Most cases of hypercalcaemia are secondary to malignancy or primary hyperparathyroidism. We report a patient presenting with a triad of hypercalcemia, metabolic alkalosis, and renal failure secondary to treatment of iatrogenic hypoparathyroidism and osteoporosis. Persistent ingestion of calcium carbonate and vitamin D caused milk-alkali syndrome. The patient was managed with intravenous fluids and withdrawal of calcium carbonate and vitamin D. She responded well to the treatment and the calcium concentration, renal function and metabolic alkalosis were normalized. Milk-alkali syndrome may be important as a reemerging cause of hypercalcemia.
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PMID:Hypercalcemia associated with acute kidney injury and metabolic alkalosis. 2146 3

We reported a case of a 41-year-old woman who had been diagnosed with Gitelman's syndrome since the age of 31 years. The diagnosis was established by the typical biochemical pictures including renal wasting hypokalemia, hypomagnesemia, hypocalciuria, metabolic alkalosis, and hyperreninemic hyperaldosteronism. She had normal blood pressure and had never used diuretics. She had a sibling with similar syndrome. The patient was treated with oral potassium and magnesium supplementation. She began to have hypercalcemia at the age of 39 years. The diagnostic approach to hypercalcemia became more complicated because of normal parathyroid hormone levels and underlying hypocalciuria due to Gitelman's syndrome. Thorough evaluation eventually identified primary hyperparathyroidism as the cause of hypercalcemia. To our best knowledge, this is the first report of combined occurrence of Gitelman's syndrome and primary hyperparathyroidism in the literature.
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PMID:An unusual case of Gitelman's syndrome with hypercalcemia. 2229 9

Solute Carrier Family 12 member 1 (SLC12A1) gene encodes the sodium-potassium-chloride co-transporter (NKCC2) at the apical membrane of the thick ascending loop of Henle (TAL). Bartter's syndrome (BS) type I is a rare, autosomal recessive, renal tubular disorder associated with mutation of the SLC12A1 gene. Presenting features include: hypokalemic metabolic alkalosis, hypercalciuria and nephrocalcinosis. The many allelic variants reported present with a spectrum of phenotypes, biochemical abnormalities and clinical severities. However, to date, only two reports have described hyperparathyroidism and hypercalcemia in patients with SLC12A1 gene mutations. We describe 4 patients with 4 novel mutation variants in the SLC12A1 gene (c.735C>G, c.1137del, c.2498-2499del, and c.1833delT) presenting with variable degrees of hyperparathyroidism, hypercalcemia, hypokalemic metabolic alkalosis, nephrocalcinosis, and nephrogenic diabetes insipidus. The link between calcium and parathyroid hormone abnormalities in patients with SLC12A1 mutations is unclear; the cases described suggest an association between primary hyperparathyroidism and loss of function mutation of SLC12A1, which may result in an aberrant threshold of the calcium sensing receptor at the level of the kidney.
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PMID:A novel SLC12A1 gene mutation associated with hyperparathyroidism, hypercalcemia, nephrogenic diabetes insipidus, and nephrocalcinosis in four patients. 2809 94


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