Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0205700 (ash)
 15,125 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Besides rickets and osteomalacia, the X-linked hypophosphatemic male mouse (Hyp/Y) presents with low serum calcium (Ca) and increased urinary hydroxyproline (OH-Pro) excretion, suggesting a parathyroid hormone (PTH)-stimulated bone resorption despite reduced magnesium (Mg) bone content. In this study, we have investigated by histochemical methods the state of bone resorption in 50-day-old untreated Hyp/Y mice and the effects of 4 wk of Mg therapy or dietary lactose supplementation on bone formation and resorption. Mineral and skeletal changes were evaluated on serum, urinary and bone ash concentrations of Ca, phosphorus (P) and Mg, and by histomorphometric analysis of tetracycline double labeled undeclalcified caudal vertebrae. The number of acid phosphatase stained chondroclasts and osteoclasts was lower than normal in untreated Hyp/Y and was restored after Mg therapy while the osteoclastic surface was increased above normal. Accordingly, serum P and urinary Ca, P, Mg, cAMP and OH-Pro were increased while TmP/GFR was unchanged. On the other hand, dietary lactose corrected serum Ca which probably suppressed PTH secretion since the renal P conservation was improved and the osteoclast number and the osteoclastic surface were decreased. Both treatments reduced the growthplate and osteoid seam thickness and increased the bone calcification rate. The results indicate that the low skeletal Mg present in Hyp/Y partially impairs bone responsiveness to PTH since Mg therapy restored the osteoclastic bone resorption which secondarily provided new minerals for bone mineralization. The greater than normal bone resorption found in Mg treated-Hyp/Y and the decreased bone resorption observed in lactose treated animals indicate that the chronic hypocalcemia induces secondary hyperparathyroidism in Hyp/Y mice.
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PMID:Effects of magnesium and lactose supplementation on bone metabolism in the X-linked hypophosphatemic mouse. 682 87

This study was undertaken to determine whether dietary supplements of NaCl would exaggerate osteopenia in oophorectomized (OOPX) rats consuming a low calcium (0.01% Ca) diet. Thirty 300 g OOPX rats with 45Ca-labeled bones were studied. Animals in group 1 were killed at the start of the experiment, whereas those in groups 2 and 3 were fed a low calcium diet for 2 months. Group 3 rats received NaCl (8 g/100 g diet). Salt increased the urinary excretion of sodium, calcium, phosphate, cyclic AMP, 45Ca and hydroxyproline but did not augment fecal excretion of calcium or 45Ca. Salt caused bone loss. The femora of NaCl-treated rats contained less 45Ca, less calcium, less phosphate and less mineral ash than those of rats killed at the start of the experiment. It is suggested that in OOPX rats consuming a low calcium diet, increased NaCl intake causes decreased renal tubular reabsorption of calcium and consequently lowered plasma Ca++. This results in stimulation of parathyroid hormone secretion and thus increased bone resorption. We conclude that NaCl supplements exacerbate osteopenia in adult OOPX rats consuming a low calcium diet. The effects of high dietary salt intakes on bone loss in postmenopausal women deserve further study.
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PMID:Dietary NaCl loads promote calciuria and bone loss in adult oophorectomized rats consuming a low calcium diet. 686 39

The purpose of this study was to determine how bone remodeling changes induced by nutritional hyperparathyroidism affect tooth movement through alveolar bone. Twelve beagle dogs, approximately 1 year old, were randomly divided into two groups of six. The controls were fed a standard dog diet (calcium 0.54 percent, phosphorus 0.42 percent). The experimental diet was identical to that fed the controls except for a decrease in the calcium (0.12 percent) to phosphorus (1.20 percent) ratio. At the tenth week of diet administration, following extraction of the lower third premolars, the second and fourth premolars were moved toward each other with a reciprocal elastic force of 100 Gm. Twelve weeks later the animals were killed and the mandibles were prepared for laboratory evaluation, which included Paragon 1301 staining of undecalcified sections, scanning electron microscopy, and a bone ash analysis. Radioimmunoassays during the experiment showed that the test animals had significantly elevated levels of parathyroid hormone, indicating a probable state of hyperparathyroidism. The clinical data revealed more rapid tooth movement in the experimental animals. Laboratory data indicated that the hyperparathyroid animals had significantly decreased bone density, as well as bone remodeling changes consistent with high PTH levels. These findings suggest that, in addition to applied force, tooth movement is dependent upon the state of calcium metabolism in alveolar bone.
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PMID:The effect of altered bone metabolism on orthodontic tooth movement. 694 49

Previous studies have shown that parathyroid hormone (PTH) monotherapy and cotherapy with estrogen or risedronate augment vertebral bone mass and bone strength in young, ovariectomized (OVX) rats. The current study was designed to determine whether PTH has similar bone anabolic effects in aged OVX rats at a much later stage of estrogen depletion. Female Sprague Dawley rats were subjected to sham surgery or bilateral ovariectomy at three months of age and maintained untreated for one year after surgery to allow for the development of vertebral osteopenia in OVX rats. Groups of baseline control and OVX rats were sacrificed at the end of this pretreatment period. The remaining OVX rats were then treated for ten weeks with vehicle, antiresorptive agents alone (estrogen, risedronate, or calcitonin), or PTH alone. Other groups of OVX rats were treated concurrently with PTH and each of the antiresorptive agents. The first and fourth lumbar vertebral bodies were processed undecalcified for quantitative bone histomorphometry and biomechanical testing, respectively. As expected, bone mass and compressive strength were decreased in the lumbar vertebral body of baseline OVX rats compared to baseline control rats. This bone loss was associated with decreases in trabecular number and width and an increase in trabecular separation. Treatment with estrogen, risedronate, or calcitonin alone failed to reverse the changes in bone mass, structure, and strength induced by ovariectomy. In contrast, treatment of OVX rats with PTH alone restored vertebral cancellous bone volume and ash density to the level of vehicle-treated control rats and increased vertebral maximum load, stress, and normalized load to well above this level.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Parathyroid hormone monotherapy and cotherapy with antiresorptive agents restore vertebral bone mass and strength in aged ovariectomized rats. 766 39

We compared the sensitivity of aurin tricarboxylic acid (ATA) or acid solochrome azurine (ASA) for detecting bone aluminum histochemically in 87 biopsy specimens obtained between 1983 and 1987 from 84 patients receiving dialysis therapy. Two consecutive biopsy sections were stained, one with ATA and the other with ASA, and then interpreted independently by two experienced observers. Three groups were established: group 1 (N = 61) had positive results of both ATA and ASA staining, group 2 (N = 25) had negative ATA but positive ASA sections, and group 3 (N = 1) had negative results of both ATA and ASA. No significant differences existed between groups 1 and 2 for age of the patients or serum calcium or immunoreactive parathyroid hormone levels. Patients in group 1 had significantly higher bone aluminium content (110 versus 61 micrograms/g dry ash weight), higher serum aluminum levels (151 versus 26 ng/ml), and longer duration of dialysis (85 versus 30 months) than did patients in group 2. Bone biopsy diagnoses (group 1 versus group 2) included low-turnover bone disease, 8 versus 7; osteomalacia, 26 versus 0; mixed uremic bone disease, 10 versus 1; hyperparathyroidism, 12 versus 14; and mild uremic bone disease, 5 versus 4. On the basis of ATA staining, 7 of 15 patients with low-turnover and 1 of 11 patients with mixed uremic bone disease may have been incorrectly diagnosed as having non-aluminum-related bone disorders. The levels of bone and serum aluminum were lower in group 2 than in group 1 but still much higher than normal.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Detection of subtle aluminum-related renal osteodystrophy. 768 73

The aim of the study was to determine the effect of parathyroid hormone (PTH), the antiresorptive agents estrogen and bisphosphonate (risedronate), and also the combination of PTH with these antiresorptive drugs on femoral cortical bone mass, dimensions and strength in a sexually mature, ovariectomized rat model. A total of 138, 3-month-old Sprague-Dawley rats were randomized into seven groups: 1--sham operated (control); 2--ovariectomized (OVX); 3--OVX plus estrogen; 4--OVX plus bisphosphonate (risedronate [NE]; 5--OVX plus hPTH (1-34); 6--OVX plus hPTH (1-34) and estrogen; 7--OVX plus hPTH (1-34) and risedronate. Treatment regimens were initiated 4 weeks after OVX and were continued for 5 and 15 weeks for each treatment group. Changes in bone mass (ash content), cross-sectional area, cortical thickness and dimensions and bone strength were assessed in middiaphyseal, femoral specimens. The results revealed that ovariectomy had no effect on cortical bone mass and biomechanical competence. OVX rats treated with estrogen and also OVX rats treated with risedronate showed no significant difference from either OVX or control groups. After only 5 weeks of treatment, hPTH monotherapy increased ash content, cross-sectional area, cortical thickness and compressive bone strength (load) significantly. After 15 weeks of treatment, OVX rats treated with PTH monotherapy or PTH in combination with risedronate showed identical load-values. These values were significantly higher than those seen in both control and OVX rats. However, PTH in combination with estrogen failed to augment cortical bone strength over control or OVX levels after therapy.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The anabolic effects of parathyroid hormone on cortical bone mass, dimensions and strength--assessed in a sexually mature, ovariectomized rat model. 775 51

An experiment was carried out to investigate the effects of age of laying hens (young = 22 wk vs old = 120 wk) in maintaining Ca homeostasis during periods of Ca depletion then repletion with Ca. Plasma Ca and P, tibia breaking strength and percentage ash, renal 25-hydroxycholecalciferol-1-hydroxylase (1 alpha-hydroxylase), and parathyroid hormone (PTH)-stimulated adenylate cyclase activities were studied during 28 d of Ca depletion on a .08% Ca diet (LC) and 28 d of Ca repletion on a 3.75% Ca diet (HC). When laying hens on a HC diet were placed on a LC diet, plasma Ca and P, tibia breaking strength and ash percentage, and renal PTH-dependent adenylate cyclase activity were significantly depressed, but renal 1 alpha-hydroxylase activity was significantly stimulated. These changes were greater in the young hens than in the older hens; therefore an interaction between age and dietary Ca was found. These changes were of a lesser magnitude at 28 d of Ca depletion, probably due to the cessation of egg laying and to the desensitization of hormone-mediated function. 1 alpha-Hydroxylase activity was significantly less during the repletion period. The age effect was most pronounced for 1 alpha-hydroxylase, with the younger birds expressing significantly higher activity and ability to respond to hypocalcemia. There was a significant increase in kidney weights in Ca-deficient groups at 14 and 28 d of Ca depletion. It is concluded that younger hens have greater adaptive responses to Ca restriction than do older hens.
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PMID:Calcium homeostasis in the laying hen. 1. Age and dietary calcium effects. 781 33

The majority of hemodialysis patients die from cardiovascular disease. However, the contribution of myocardial infarction to mortality is relatively minor, despite the fact that coronary artery disease is common in uremic patients. Hypertension seems to be the major risk factor for the development of atherosclerosis in hemodialysis patients, although abnormalities of the lipid spectrum, characterized by an increase in triglycerides and very low density lipoprotein levels and a decrease in high-density lipoprotein levels, are frequent in hemodialysis patients. The existence of left ventricular (LV) hypertrophy is a serious risk factor for morbidity and mortality in hemodialysis patients. LV hypertrophy can present as a dilated cardiomyopathy or as concentric or asymmetric septal hypertrophy. Loss of myocardial contractility by coronary artery disease or carnitine deficiency can lead to systolic LV dysfunction with a compensatory dilated cardiomyopathy. Furthermore, the presence of a hypercirculation in uremic patients, resulting from anemia, the arteriovenous fistula, or fluid overload, can also lead to a dilated cardiomyopathy. Systolic LV dysfunction occurs when the increase in LV wall thickness is inadequate for the increase in LV radius, which might be caused by increased levels of parathyroid hormone. LV diastolic dysfunction, resulting from an increase in LV mass due to the effects of hypertension or to uremic interstitial fibrosis, can both lead to pulmonary edema and hypotensive periods during hemodialysis and is a severe risk factor for mortality in hemodialysis patients. Therefore, in uremic patients, anemia should be corrected and hypertension adequately treated early in the development of renal failure. Chronic fluid overload should be prevented by adequate estimation of optimal dry weight.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Cardiovascular aspects in renal disease. 792 20

The effect of parathyroid hormone (PTH(1-34)) on mid-diaphyseal femoral cortical bone was studied in 2-year-old male rats. The rats were treated with daily injections of 15 nmol/kg PTH(1-34) or vehicle for 56 days, and labelled with tetracycline and calcein on day 15 and day 40, respectively. The PTH(1-34) treatment did not affect the body weights or the lengths of the femora. Fluorescence microscopy showed large intracortical cavities in the old vehicle-treated rats. After PTH treatment, double labelling and new bone formation filling in these cavities were found. Furthermore, an increased bone formation rate was observed both at the periosteum and at the endosteum. This resulted in an increase in the cross-sectional area and a decrease in the medullary area. Three-point bending analysis revealed an increase in ultimate load, ultimate stiffness, energy absorption and ultimate stress after the PTH(1-34) treatment. No differences were found between the groups regarding the hydroxyproline concentration or apparent and real densities. The ash concentration was, however, slightly reduced after PTH(1-34) treatment. The PTH(1-34) treatment of old rats induced the formation of bone both from the periosteum and endosteum, with a pronounced filling in of intracortical cavities, and, furthermore, a marked increase in the biomechanical competence of the cortical bone.
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PMID:Human parathyroid hormone(1-34) increases bone formation and strength of cortical bone in aged rats. 813 Aug 97

Bone atrophy following replantation of an amputated extremity is related to the decrease of blood flow and to disuse. The effect of parathyroid hormone (PTH) on bone atrophy and bone formation was the subject of the reported study. Lewis rats were divided into amputated and replanted, and non-amputated groups, with the groups further divided into subgroups, with and without the administration of PTH. The agent (0.8 U/0.2 ml) was administered subcutaneously three times a week for 5 consecutive weeks, while controls were given 0.1 percent BSA buffer solution (0.2 ml) subcutaneously three times a week for 5 consecutive weeks. Subsequently, the animals were anesthetized, blood samples were taken, and tibias were extracted before sacrifice. Laboratory evaluations included bone assays and the measurement of bone mass and volume. In the group given PTH after amputation and replantation, there was increased bone formation, together with significant increases in bone Ca, bone P, ash content volume, and volume and serum alkaline phosphatase (Al-p), in comparison with the other groups. The administration of PTH after amputation and replantation was comparatively effective in mitigating the amount of bone damage.
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PMID:Effect of parathyroid hormone (PTH) on replantation of amputated legs in a rat model. 818 66


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