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)

Sham-operated and parathyroidectomized (PTX) rats were divided into two pair-fed groups, one on a normal mineral intake (0.5% Ca, 0.3% P), the other on a regimen low in phosphorus (0.5% Ca, 0.03% P). P depletion led to a drop in plasma P and urine P, a rise in plasma Ca and a marked rise in urine Ca, a drop in serum magnesium and a rise in urine Mg. The changes were more pronounced in the PTX animals, but final values were the same in both groups. Parallel bone-seeking isotope (85Sr, 177Lu, 237Np) studies in nonablated animals revealed an increase in the urinary nuclide output and in the urine/tibia ratio in P-deficient animals. Normal and primary bone osteocytes decreased and enlarged osteocytes increased as a result of P deficiency; osteoclasts and osteoblasts also increased. Bone composition showed a drop in ash content and a rise in water, with a light decrease in both Ca and P, and a corresponding rise in hydroxyproline and nitrogen in the P-deficient animals. The results are interpreted to mean that P-deficiency in the young growing rat leads to an increase in bone resorption which occurs also in the absence of parathyroid hormone (PTH). The fact that final values were similar in the control and PTX P-deficient animals suggests that steady-state regulation can also occur without PTH. Because P-deficiency leads to rapid hypercalcemia and rapid marked hypercalciuria, there may exist a mechanism for phosphate regulation which would then supersede Ca homeostasis. The change in serum and urine Mg levels may reflect a decrease in tubular Ca and Mg reabsorption associated with P-deficiency.
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PMID:Phosphorus deficiency, parathyroid hormone and bone resorption in the growing rat. 95 82

Some cereal by-products, such as bran, exhibit a high phytase activity that may enhance phytate P digestibility. This was studied in growing pigs fed a phytase-rich (1,200 IU/kg) diet containing 20% rye bran. The trial involved 12 animals; six were fed a control diet and six were fed a diet containing rye bran for 2 mo. Both diets contained the same levels of energy, protein, Ca (.7%) and total P (.4%). No inorganic P was added; thus, the dietary P was mainly phytic. Pigs fed the control diet, in contrast to those fed the diet containing rye bran, developed a P deficiency, as indicated by hypophosphatemia, hypophosphaturia, hyperhydroxyprolinuria, hypercalcemia, and hypercalciuria. Phosphorus from the rye bran diet was more completely absorbed (55 vs 36%) and retained (50 vs 36%) than that from the control diet. Calcium absorption was equal for the two diets, but Ca retention was higher in pigs fed rye bran than in controls. Pigs fed the rye bran diet showed greater bone density, ash content, and bending moments than controls. In conclusion, high dietary phytase levels or phytase-rich by-products increased phytate P availability and consequently improved bone scores.
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PMID:Enhancement of phosphorus utilization in growing pigs fed phytate-rich diets by using rye bran. 164 62

Diabetes mellitus was induced in Lewis rats by streptozotocin, and these animals and control rats fed ad lib were studied after 7 weeks. At the time of sacrifice, nondecalcified histological sections of bone were prepared and subsequently quantitated by micromorphometric techniques. In addition, tibial alkaline phosphatase and mineral ash content were determined. The bones obtained from the diabetic animals are characterized by significant decrements in the quantities of osteoid and osteoclasts and by failure to acquire a tetracycline label. These histological features are attended by reduced quantities of urinary hydroxyproline and tibial alkaline phosphatase. As compared with control animals fed ad lib, diabetic rats are hyperphosphatemic and markedly hypercalciuric. Circulating alkaline phosphatase is also elevated and associated with a parallel increase in intestinal content of this enzyme. Although serum corticosterone levels are increased, diabetes is associated with decrements in both circulating immunoreactive parathyroid hormone and 1,25(OH)2D. We conclude that prolonged streptozotocin-induced diabetes mellitus in the rat results in reduced bone turnover. The relative roles that functional caloric deprivation, low circulating levels of 1,25(OH)2D, hypercalciuria, hypercortisolemia, and decreased blood parathyroid hormone levels play in the genesis of these skeletal abnormalities remain to be determined.
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PMID:The effect of streptozotocin-induced chronic diabetes mellitus on bone and mineral homeostasis in the rat. 645 Feb 54

The influence of experimental colitis, induced by trinitrobenzenesulphonic acid with ethanol, on bone mineralisation and mineral metabolism was investigated in male rats. Three days after colitis induction, there was a significant rise (p < 0.01) in urinary calcium excretion, which was still present 20 days later (p < 0.05). Three weeks after colitis induction, urinary hydroxyproline excretion was significantly increased (p < 0.01), while urinary cyclic AMP and phosphorus decreased. Colitis was associated with reduced bone density (p < 0.025), ash weight (p < 0.05) and calcium/volume ratio (p < 0.05), whereas no change was found for bone volume and the phosphorus/volume and magnesium/volume ratios. Serum minerals remained unchanged. We conclude that chronic experimental colitis in the rat leads to resorptive hypercalciuria, increased urinary hydroxyproline and osteopenia. Considering site of inflammation, diet, sex, and absence of therapy, inflammatory mediators, e.g. cytokines, with known catabolic effects on bone, might be involved in the pathogenesis of osteopenia.
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PMID:Effect of experimental colitis on bone metabolism in the rat. 806 26

A disturbed calcium homeostasis characterizes diabetic pregnancy. This study documents changes in bone mineral composition in diabetic pregnant rats and examines the effect of insulin replacement. Control pregnant (CP), diabetic pregnant (DP) and insulin-treated DP (DPi) rats were assessed for femoral calcium and magnesium content, bone mineral density (BMD) and the ratio of hypertrophic to maturing and proliferative cells in the femoral growth plate. DP rats showed a significantly (P < 0.01) lower body weight, femoral weight and length than CP rats. Femoral calcium and magnesium content was also significantly (P < 0.05) lower in DP rats, as was ash weight. When calcium and magnesium were normalized for ash weight no significant differences were apparent. A significantly (P < 0.05) lower total BMD at the distal femur was seen in DP rats. This comprised a significantly (P < 0.01) lower trabecular BMD with no significant change in cortical BMD. A significantly (P < 0.05) higher ratio of hypertrophic to maturing and proliferative cells of the femoral growth plate was evident in DP animals. DPi rats showed normal blood glucose concentrations and femoral growth plate histology. DPi rats also showed normal femoral weight and length but only partially restored femoral ash weight and mineral content. Insulin failed to normalize total or trabecular BMD. Diabetes mellitus clearly has a marked effect on bone growth and mineral content in pregnancy which may be relevant to overall calcium homeostasis. The lower bone growth, bone calcium content and trabecular BMD may be unfortunate consequences of the marked hypercalciuria reported elsewhere in diabetes and may serve to maintain normocalcaemia in the disease.
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PMID:Bone mineral density and composition in rat pregnancy: effects of streptozotocin-induced diabetes mellitus and insulin replacement. 956 76