Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020438 (hypercalciuria)
 2,502 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Studies were performed on 12 patients with idiopathic hypercalciuria to evaluate the hypothesis that the acid load accompanying potassium acid phosphate would adversely affect renal calcium reabsorption and citrate excretion compared to the neutral form of the phosphate salt. During acute clearance studies, neutral phosphate (NP) led to a fall in FECa (2.2 +/- 0.6% to 0.8 +/- 0.1%, P less than 0.02) and no change in titratable acidity (TA) or net acid excretion (NAE). Acid phosphate (AP) did not reduce FECa acutely, and led to a rise in TA (22 +/- 4 to 62 +/- 6 muEq/min, P less than 0.02) and NAE (46 +/- 6 to 6 89 +/- 7 muEq/min, P less than 0.02). During chronic administration, AP resulted in higher urinary calcium excretion in both absorptive (187 +/- 29 vs. 141 +/- 18 mg/day, P less than 0.02) and renal hypercalciuric patients (233 +/- 24 vs. 173 +/- 190.02 mg/day, P less than 0.02). Also, TA and NAE were higher following AP, whereas citrate excretion was lower (375.4 +/- 64.6 vs. 633.4 +/- 28.8 mg/day, P less than 0.01). These data suggest that the reported ineffectiveness of AP in the therapy of nephrolithiasis may be related to the deleterious effects of the acid load on calcium and citrate metabolism.
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PMID:Differing effects of acid versus neutral phosphate therapy of hypercalciuria. 4 88

The association of hypercalciuria, salt losing renal disease, and a defect in urine concentrating ability with high renin and aldosterone levels is described in two brothers. One child had marked nephrocalcinosis by the age of 3 and the other severe growth retardation. In one child all the abnormalities were abolished with indomethacin which was responsible for a marked decrease in urinary. The data and the family study suggest that this condition is a proximal tubular disorder with atuosomal recessive inheritance.
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PMID:[Familial tubulopathy associating hypercalciuria and saline diabetes. Favorable results of indomethacin therapy]. 48 70

In an effort to maintain normal serum calcium levels without inducing hypercalciuria, we treated seven hypoparathyroid patients for up to 25 months with chlorthalidone, a thiazide-like sulfonamide diuretic, plus a salt-restricted diet, without added vitamin D. Mean 24-hour calcium excretion decreased from 179 to 88 mg (P less than 0.001), and mean serum calcium increased from 8.2 to 9.3 mg per deciliter (P less than 0.05). Diuretic therapy or moderate salt restriction alone was not as effective as combined therapy. Beneficial effects were sustained for as long as therapy was maintained. The rise in serum calcium, which involves the filterable and ionized fractions, cannot be due entirely to reduced excretion and may in part be explained by increased intestinal absorption. Oral chlorthalidone plus a low salt diet appears to be an effective alternative to vitamin D in the maintenance therapy of at least some patients with hypoparathyroidism.
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PMID:Treatment of hypoparathyroid patients with chlorthalidone. 62 74

The effects of acute and chronic metabolic acidosis on serum immunoreactive parathyroid hormone (iPTH) were studied. Acute metabolic acidosis induced by administration of ammonium chloride (NH4Cl) produced a barely detectable increase in serum iPTH. Chronic NH4Cl administration produced a marked elevation of serum iPTH that was well correlated with the magnitude of acid-induced hypercalciuria but not with the degree of acidosis. Acetazolamide administration produced an equivalent degree of acidosis, but hypercalciuria was minimal and iPTH increased only marginally. Methionine administration caused moderate hypercalciuria and a significant but moderate increase in iPTH. Chronic NH4Cl-induced acidosis produced no hypercalciuria when dietary sodium intake was rigidly restricted, and under these conditions serum iPTH remained normal. When sodium intake was suddenly increased while maintaining the acid load, hypercalciuria appeared and was followed by progressive rise in serum iPTH equivalent to that observed during chronic NH4Cl-induced acidosis in subjects consuming salt ad lib. These results indicate that chronic acidosis elevates iPTH mainly by producing hypercalciuria and that acidosis itself is not a primary stimulus to PTH secretion.
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PMID:Effect of acute and chronic metabolic acidosis on serum immunoreactive parathyroid hormone in man. 120 55

Renal failure was found in a five-year-old patient who had been treated with insulin since he was diagnosed as having insulin dependent diabetes mellitus (IDDM) at 3 years of age. Laboratory data showed that his renal failure was caused by a renal tubular dysfunction. The autopsy findings of his pancreas were compatible with those of IDDM. The kidneys were atrophied with an innumerable number of crystals in the proximal tubuli. Staining by Kossa indicated that the crystals contained calcium salt. The calcium content of his kidneys was significantly higher than that of control. The nephrocalcinosis seems to be caused by hypercalciuria associated with IDDM.
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PMID:Insulin dependent diabetes mellitus accompanied by nephrocalcinosis and renal failure. 144 54

To assess a possible heritability of a disturbed calcium metabolism in relation to blood pressure regulation, 28 young normotensive offspring of either hypertensive or normotensive parents were studied while administered a defined diet with daily sodium chloride of 6 and 20 g/day for 7 days each. Before the high salt diet was begun, the cytosolic calcium concentration ([Ca2+]i) in platelets was elevated in offspring of hypertensive parents, whereas serum electrolytes, plasma renin activity, plasma catecholamines, and 24-hour urinary excretion of sodium and calcium showed no difference between the two groups. On exposure to a high salt diet, the mean blood pressure increased (from 80 +/- 2 to 85 +/- 2 mm Hg, p less than 0.05) in offspring of hypertensive parents. These changes in mean blood pressure were positively correlated with the basal platelet [Ca2+]i (r = 0.61, p less than 0.01), whereas [Ca2+]i did not demonstrate any significant changes. When the subjects were administered the high salt diet, plasma ionized calcium decreased (from 2.37 to 2.21 meq/l, p less than 0.05) and 1,25-dihydroxyvitamin D3 increased (from 32.7 to 40.8 pg/ml, p less than 0.05) with a transient relative hypercalciuria in offspring of hypertensive parents. This increase of 1,25-dihydroxyvitamin D3 was significantly correlated with the changes in mean blood pressure (r = 0.62, p less than 0.01). Disturbed intraplatelet and systemic calcium metabolism may be of predictive value in the development of hypertension.
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PMID:Disturbed calcium metabolism in offspring of hypertensive parents. 159 47

The effects of salt (sodium chloride) supplementation of rat diets (80 g/kg diet), with or without lactose (150 g/kg), were studied in weanling rats over 14 d. Dietary salt increased water intake and reduced weight gain and food conversion efficiency, but these variables were unaffected by lactose. Salt-supplemented rats exhibited a three- to fivefold increase in urinary calcium excretion and a small increase in urinary magnesium and phosphorus excretion, irrespective of dietary lactose content. In addition, salt supplementation reduced plasma alkaline phosphatase (EC 3.1.3.1) activity. Lactose increased urinary Ca and Mg excretion and plasma Ca and P concentrations. Salt reduced tibia mass but not tibia mass expressed relative to body-weight, but neither variable was affected by lactose. Both tibia Mg content and concentration were reduced by salt but unaffected by lactose, and neither tibia P content nor concentration was affected by salt or lactose. Tibia Ca content was reduced by salt but this was prevented by lactose. Tibia Ca concentration was unaffected by salt or lactose, although there was a reduction (not significant) in tibia Ca concentration in animals fed on the lactose-free diet. These results show that lactose had no independent effect on bone and that reduced accretion of bone mass and mineral content in rats fed on the high-salt diets was due, at least in part, to reduced growth. Failure to offset sodium-induced hypercalciuria by a compensatory increase in net Ca absorption may have contributed to reduced bone Ca accretion. The protective effect of lactose against reduced bone Ca accretion may be due to increased Ca absorption.
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PMID:Effect of dietary lactose on salt-mediated changes in mineral metabolism and bone composition in the rat. 193 8

We present what we believe is the first case of rickets following prolonged treatment with aluminum containing antacids that bind phosphate, in an 18-year-old mentally retarded boy with cerebral palsy and spastic quadriplegia. As expected, serum calcitriol was increased and urinary phosphate excretion was very low. However, in contrast to all published cases of antacid induced hypophosphatemic osteomalacia in adults, despite a substantial increase in bone resorption reflected by urinary total hydroxyproline excretion, urinary calcium excretion was low rather than high, and significant hypocalcemia occurred after antacids were ceased and a phosphate salt administered. We suggest that the skeleton was so under-mineralized because of growth during prolonged phosphate deficiency, possibly augmented by anticonvulsant administration and immobilization, that increased bone resorption did not release enough calcium to cause hypercalciuria, or to prevent hypocalcemia during resumption of normal mineralization.
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PMID:Hypophosphatemic rickets with hypocalciuria following long-term treatment with aluminum-containing antacid. 179 81

Shortly after the introduction of the thiazide diuretics it was noted that they lower the excretion of Ca2+ in the urine, enough so that they were introduced for the therapy of hypercalciuria in calcareous stone formers. This observation prompted us to begin a series of investigations designed to better understand the handling of Ca2+ by the kidney in general, and the effects of diuretics on Ca2+ transport in particular. Since it was already known that the excretion of Ca2+ followed closely the excretion of Na+ we postulated that the effects of diuretics are related to the shrinkage of extracellular (ECF) volume which signals the kidney to enhance filtrate absorption particularly in the proximal tubule. This we supported with studies showing that calcium excretion will return to the original elevated level, inspite of continued administration of the diuretic, if a high salt intake were allowed. We also showed the opposite, namely that hypercalciuria can be produced by mineralocorticoid administration if liberal salt intake were allowed, and is prevented by salt restriction. This latter observation antedated the clinical observation that primary aldosteronism is accompanied by hypercalciuria. These studies clearly showed the importance of ECF volume in determining urinary excretion of Ca2+. The site of action in the nephron of volume changes was thought to be the proximal convoluted tubule. Volume expansion had already been shown to depress proximal tubular absorption of Ca2+. We carried out studies using in situ micropuncture and demonstrated that ECF volume depletion caused by thiazide diuretics results in enhanced absorption in the proximal tubule confirming the suspicion that changes in ECF volume were translated into reciprocal changes in proximal tubular absorption. Meanwhile we showed that a different group of diuretics, the high-ceiling diuretics, unlike the thiazides produce a major increase in Ca2+ excretion suggesting that they exert their effects at a different site in the nephron, namely the loop of Henle. These and many other studies dictated that we examine more directly the handling of Ca2+ by the kidney, and for that purpose we employed the technic of in vitro microperfusion of isolated renal tubule segments. In the S2 segment of the proximal convoluted tubule we were able to show that Ca2+ absorption was entirely passive, following the electrochemical gradient for calcium present in this segment (luminal PD positive, tubular fluid [Ca2+] greater than plasma [Ca2+]).(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Calcium and the kidney--from stones to molecules. 222 31

To examine the effects of mineralocorticoidism on calcium (Ca) absorption and to define the mechanism, rats received a high-salt diet and injections of vehicle or deoxycorticosterone acetate (DOCA). Net (44.2 vs. 31.4 mg/day) and percent Ca absorption (28.1 vs. 20.1%) was increased after 5 days of DOCA. This was associated with increased duodenal 45Ca uptake. Thus despite the hypercalciuria, Ca balance was similar. Although the hypercalciuria persisted chronically, the gut effects were sustained, which maintained normal ionized Ca, bone Ca, and Ca balance. Urinary cyclic adenosine monophosphate was elevated by DOCA. Compared with appropriate controls, neither DOCA alone nor polydipsia (elicited by dextrose) produced similar magnitudes of hypercalciuria as DOCA plus high-salt diet. These maneuvers also failed to increase Ca absorption. Neutralization of the metabolic alkalosis neither attenuated the DOCA-induced hypercalciuria nor abolished the Ca hyperabsorption. In vitamin D-deprived rats, the hypercalciuria but not the intestinal effects of DOCA were reproduced. Serum 1,25-dihydroxyvitamin D3 levels were increased during chronic DOCA treatment (224 vs. 139 pg/ml). These data best fit the hypothesis that increased Ca absorption is secondary to the calciuric effects of DOCA and high-salt diet and is mediated via the increased parathyroid hormone and 1,25-dihydroxyvitamin D3 activities.
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PMID:Chronic DOCA treatment increases Ca absorption: role of hypercalciuria and vitamin D. 301 51


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