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

Rats rendered chronically hyperprolactinemic by implantation of extra anterior pituitary glands (AP) under the kidney capsule have excess urinary calcium excretion. Although serum testosterone levels are normal in male AP-grafted rats, more subtle androgen deficiency might contribute to the increased calcium loss. Female AP-grafted rats lose the normal estrous cycle, which might also alter calcium homeostasis. The urinary calcium and calcium/sodium excretion ratio in gonadectomized AP-grafted rats of both sexes were compared with that of otherwise intact AP-grafted rats and muscle-grafted control rats. AP-grafted rats had increased urinary calcium excretion and calcium/sodium excretion ratio, regardless of gonadal status. Treatment of castrated male AP-grafted animals with testosterone or dihydrotestosterone did not have a significant effect on urinary calcium loss, nor did estrogen replacement of ovariectomized female AP-grafted rats. These studies indicate that the hypercalciuria of the AP-grafted rat is not mediated via an anti-gonadal effect of the prolactin-secreting pituitary graft.
 ...
PMID:Hypogonadism does not mediate urinary calcium loss in pituitary-grafted rats. 276 18

A 28-year-old male presented with profound hypokalemia and was found to have a variant of Bartter's syndrome with nephrocalcinosis, hypercalciuria, normal distal fractional reabsorption of chloride and normal sodium delivery to the distal tubule.
 ...
PMID:Hypokalemia with nephrocalcinosis: a variant of Bartter's syndrome. 276 7

The aim of this study was to investigate the pathogenesis of hypercalciuria in the Milan strain of genetically hypertensive rats. Dietary calcium intake and urinary and fecal calcium output were measured simultaneously with indices of sodium and phosphate homeostasis in male rats of the Milan hypertensive and normotensive strains. In addition, urinary calcium and creatinine excretion rates, calcium, phosphate and creatinine serum concentrations, and bone calcium content were also measured in these rats after an overnight fast. Under fed steady-state conditions dietary calcium, sodium, and phosphate intakes, were similar in the two groups of rats, but hypertensive rats had twofold higher urinary calcium excretion and normal urinary excretion of sodium and phosphate. Fecal calcium output was slightly but significantly higher in the adult hypertensive rats while fecal sodium and phosphate excretion was normal. Because of increased urinary and fecal calcium loss, net calcium balance was significantly less positive in hypertensive than in control rats. Under fasting conditions hypertensive rats were confirmed to have hypercalciuria despite normal serum calcium concentrations and normal creatinine clearance. In accordance with balance data and fasting hypercalciuria, bone calcium content was found to be significantly reduced in hypertensive rats. These findings confirm that hypercalciuria in the Milan hypertensive rats is explained by an altered renal calcium handling; it is also associated with a slightly increased fecal calcium output and, therefore, with a less positive calcium balance and reduced bone calcium content.
 ...
PMID:On the pathogenetic mechanism of hypercalciuria in genetically hypertensive rats of the Milan strain. 280 68

The effects of glucocorticoids on calcium and bone metabolism were investigated in 11 children (aged 6 months to 13 years) who were treated with dexamethasone, prednisolone and depot-ACTH because of different disorders. Alkaline phosphatase activity and osteocalcin in serum, representing indices of osteoblastic bone synthesis, and urinary hydroxyproline in relation to creatinine in morning fasting urine specimens, an index of osteoclastic bone degradation, decreased by 53-61% from baseline (P less than 0.01), with a highly significant relationship of all 3 indices to each other. Additional influences of glucocorticoids were hyperphosphaturia due to decreased renal phosphate reabsorption not mediated by secondary hyperparathyroidism, as well as marked hypercalciuria. As the consequence of the present study the following prophylactic or therapeutic recommendations are given during steroid-treatment: 1. Approvement of the negative balance of calcium and phosphate by correcting the hypercalciuria with hydrochlorothiazide, and the hypophosphatemia with oral phosphate and 2. in elder children with osteoporosis, stimulation of the decreased osteoblastic bone formation by sodium fluoride.
 ...
PMID:[Disorders of calcium and bone metabolism in glucocorticoid treatment]. 284 91

In the present study Farnolith (a granular powder consisting of different dietary fibres) was given to normals (n = 6), patients suffering from absorptive hypercalciuria type I (n = 6) and to one patient suffering from renal hypercalciuria. Farnolith binds calcium and reduces the calcium absorption from the intestine. In normals the urine- and serum parameters of calcium metabolism (total- and ionised calcium, parathyroid hormone and vitamin-D-metabolites) remained unchanged. In patients suffering from absorptive hypercalciuria type I a significant reduction of hypercalciuria was found; oxalic acid excretion had decreased as well. Lowered parathyroid hormone values returned to normal, vitamin-D-metabolites remained unaffected. In one patient suffering from renal hypercalciuria parathyroid hormone and 1,25-dihydroxy-vitamin D values increased, calcium excretion had not decreased, though. Our investigation shows that Farnolith is suitable for the treatment of absorptive hypercalciuria. Calcium homoeostasis is returned to normal by Farnolith, at the same time it does not produce secondary hyperoxaluria (as e.g. sodium cellulose phosphate). Patients with primary renal calcium loss should not be treated by Farnolith.
 ...
PMID:Calcium metabolism in normal and in hypercalciuric patients on Farnolith, a dietary fibre preparation. 285 67

Urinary volume in 24-hour urine collections was examined in 50 children with hypercalciuria and urolithiasis or hematuria, 12 with idiopathic calcium oxalate urolithiasis and 36 healthy children. Urinary volume was 22.2 +/- 2.0 ml. per kg. per day in healthy children and 25.4 +/- 2.0 ml. per kg. per day in children with hypercalciuria, and it was similar in children with absorptive and renal hypercalciuria, and significantly lower in children with idiopathic calcium oxalate urolithiasis (12.2 +/- 1.4 ml. per kg. per day, p less than 0.001 from controls and children with hypercalciuria). Volume was not statistically different in hypercalciuric children with and without urolithiasis. Urinary sodium excretion in children with idiopathic calculi was not statistically different from controls. Urine osmolality was similar among the groups. Urinary volume represents a risk factor in children with idiopathic calcium oxalate urolithiasis, and increased fluid intake should be emphasized in such patients.
 ...
PMID:Urinary volume in children with urolithiasis. 292 90

Spaceflight could provoke formation of kidney stones, in part by causing hypercalciuria and hyperphosphaturia. Applicants for spaceflight who have metabolic or environmental derangements to begin with might be particularly susceptible to stone formation in space. We, therefore, analyzed 24-h urine samples for stone-forming risk factors in 104 male applicants before their selection into the astronaut-mission specialist corps. The urinary environment was abnormally supersaturated with calcium oxalate in 25.0% of applicants, brushite in 36.5%, and monosodium urate in 66.3%, predisposing these applicants to crystallization of stone-forming calcium salts. This high level of supersaturation was caused by both "metabolic" and environmental disturbances. Thus, hypercalciuria was found in 11.5% of applicants, hyperoxaluria in 2.9%, hyperuricosuria in 18.3% and hypocitraturia in 5.8%. Environmental derangements were generally more prominent, as indicated by low urine volume of less than 2 L.d-1 in 84.6%, high urinary phosphate in 24.4%, and high urinary sodium in 10.6% of applicants. The results suggest that most of the abnormal stone risk factors disclosed among applicants for spaceflight programs were environmental in origin.
 ...
PMID:Assessing applicants to the NASA flight program for their renal stone-forming potential. 293 Apr 28

Idiopathic hypercalciuria is a common disorder whose inheritance suggests an enzyme abnormality in calcium transport. We measured calcium-magnesium-ATPase activity in erythrocytes from 38 patients (mean age [+/- SEM], 40 +/- 2.1 years) with idiopathic hypercalciuria (24-hour urinary calcium excretion greater than or equal to 0.1 mmol per kilogram of body weight) and a history of multiple calcium oxalate kidney stones. As compared with 41 healthy controls, the patients with hypercalciuria had increased erythrocyte-membrane calcium-magnesium-ATPase activity (64.2 +/- 2.19 vs. 51.6 +/- 1.91 nmol of ATP split per milligram per minute; P less than 0.01) and increased sodium-potassium pump activity (6866 +/- 233 vs. 6096 +/- 228 mumol of sodium per liter of red cells per hour; P less than 0.05). No significant difference between the two groups was found in erythrocyte sodium-potassium cotransport, sodium-lithium countertransport, or potassium content. In 66 patients with kidney stones (38 with hypercalciuria and 28 with normal calcium excretion), 24-hour urinary calcium excretion correlated with calcium-magnesium-ATPase activity (r = 0.46, P less than 0.001). Erythrocyte calcium-magnesium-ATPase activity remained unchanged in eight subjects studied after four months on a low-calcium diet. A study of 30 healthy families found significant correlations between mean values in parents and those in offspring for calcium-magnesium-ATPase (r = 0.68, P less than 0.001) and urinary calcium excretion (r = 0.45, P less than 0.02), with no significant correlations between parents with respect to these measures (r = 0.27 and r = 0.08, respectively). We conclude that abnormalities in erythrocyte calcium-magnesium-ATPase activity may represent an inherited defect in calcium transport related to the cause of idiopathic hypercalciuria.
 ...
PMID:Abnormal red-cell calcium pump in patients with idiopathic hypercalciuria. 297 Nov 39

In rats given desoxycorticosterone (DOC), the recently reported finding that a normal amount of dietary sodium chloride (NaCl) induces hypertension but an equimolar amount of sodium bicarbonate (NaHCO3) does not, might be a consequence of the differing effects of the two sodium salts on the metabolism of calcium. In accord with this hypothesis, we have found that, in uninephrectomized rats given DOC: Dietary NaCl induces persisting hypercalciuria and hypertension whereas an approximately equimolar amount of dietary NaHCO3 induces neither hypercalciuria nor hypertension. The urinary excretion of calcium becomes greater in rats given NaCl than in those given NaHCO3, before their blood pressures become different. Replacing dietary NaCl with a near equimolar amount of dietary NaHCO3 corrects both the hypercalciuria and the hypertension initially induced by NaCl.
 ...
PMID:Dietary chloride as a determinant of disordered calcium metabolism in salt-dependent hypertension. 298 59

An assay system for the measurement of the rate of Calcium Oxalate Monohydrate (COM) seed crystal growth in a metastable solution of calcium chloride and sodium oxalate containing traces of 14C-oxalic acid was used to assess the inhibitory activity of pyrophosphate (10(-5) M-10(-4) M), citrate (10(-4) M-10(-3) M) and urines of normal and pyridoxine deficient rats. Both pyrophosphate and citrate were strong inhibitors of COM crystal growth and caused a 50% decrease in crystal growth rate at 1.50 X 10(-5) M and 2.85 X 10(-4) M respectively. Normal rat urine strongly inhibited the COM crystal growth, while pyridoxine deficient animals showed a significant (p less than 0.01) decrease in mean inhibitory activity as compared to pair-fed controls. A lowered urinary inhibitory potential accompanied with hyperoxaluria and hypercalciuria, which is known to be associated with pyridoxine deficiency, may be a contributory risk of calcium oxalate crystallization and stone formation.
 ...
PMID:Inhibition of calcium oxalate monohydrate (COM) crystal growth by pyrophosphate, citrate and rat urine. 302 39


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>