acid-phosphatase and Osteomalacia

Gastrectomy (GX) is thought to result in osteomalacia due to deficiencies in Vitamin D and Ca. Using a GX rat model, we showed that GX induced high turnover of bone with hyperosteoidosis, prominent increase of mineralization and increased mRNA expression of both osteoclast-derived tartrate-resistant acid phosphatase 5b and osteocalcin. The increased 1, 25(OH)2D3 level and unchanged PTH and calcitonin levels suggested that conventional bone and Ca metabolic pathways were not involved or changed in compensation. Thus, GX-induced bone pathology was different from a typical osteomalacia. Gene expression profiles through microarray analysis and data mining using Ingenuity Pathway Analysis indicated that 612 genes were up-regulated and 1,097 genes were down-regulated in the GX bone. These genes were related functionally to connective tissue development, skeletal and muscular system development and function, Ca signaling and the role of osteoblasts, osteoclasts and chondrocytes. Network analysis indicated 9 genes (Aldehyde dehydrogenase 1 family, member A1; Aquaporin 9; Interleukin 1 receptor accessory protein; Very low density lipoprotein receptor; Periostin, osteoblast specific factor; Aggrecan; Gremlin 1; Angiopoietin-like 4; Wingless-type MMTV integration site family, member 10B) were hubs connected with tissue development and immunological diseases. These results suggest that chronic systemic inflammation might underlie the GX-induced pathological changes in bone.

Topics: Acid Phosphatase; Animals; Body Weight; Bone and Bones; Bone Diseases, Metabolic; Calcification, Physiologic; Chondrocytes; Gastrectomy; Isoenzymes; Male; Oligonucleotide Array Sequence Analysis; Osteoblasts; Osteocalcin; Osteomalacia; Rats; Rats, Wistar; Reverse Transcriptase Polymerase Chain Reaction; Tartrate-Resistant Acid Phosphatase; Tomography, X-Ray Computed; Vitamin D

Transgenic mice overexpressing fibroblast growth factor (FGF23) (R176Q) (F(Tg)) exhibit biochemical {hypophosphatemia, phosphaturia, abnormal 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] metabolism} and skeletal (rickets and osteomalacia) abnormalities attributable to FGF23 action. In vitro studies now implicate the aging-related factor Klotho in the signaling mechanism of FGF23. In this study, we used a mouse genetic approach to validate in vivo the pivotal role of Klotho in the metabolic and skeletal derangements associated with FGF23 (R176Q) overexpression. To this end, we crossed mice heterozygous for the hypomorphic Klotho allele (Kl(+/-)) to F(Tg) mice and obtained F(Tg) transgenic mice homozygous for the Kl-hypomorphic allele (F(Tg)/Kl(-/-)). Mice were killed on postnatal day 50, and serum and tissues were procured for analysis and comparison with F(Tg), wild-type, and Kl(-/-) controls. From 4 wk onward, F(Tg)/Kl(-/-) mice were clearly distinguishable from F(Tg) mice and exhibited a striking phenotypic resemblance to the Kl(-/-) controls. Serum analysis for calcium, phosphorus, parathyroid hormone, 1,25(OH)(2)D(3), and alkaline phosphatase activity confirmed the biochemical similarity between the F(Tg)/Kl(-/-) and Kl(-/-) mice and their distinctness from the F(Tg) controls. The characteristic skeletal changes associated with FGF23 (R176Q) overexpression were also dramatically reversed by the absence of Klotho. Hence the wide, unmineralized growth plates and the osteomalacic abnormalities apparent in trabecular and cortical bone were completely reversed in the F(Tg)/Kl(-/-) mice. Nevertheless, independent actions of Klotho on bone were suggested as manifested by alterations in mineralized bone, and in cortical bone volume which were observed in both the Kl(-/-) and F(Tr)/Kl(-/-) mutants. In summary, our findings substantiate in vivo the essential role of Klotho in the mechanism of action of FGF23 in view of the fact that Klotho ablation converts the biochemical and skeletal manifestations resulting from FGF23 overexpression to a phenotype consistent with Klotho deficiency.

Topics: Acid Phosphatase; Alkaline Phosphatase; Animals; Blotting, Northern; Bone Remodeling; Calcitriol; Calcium; Crosses, Genetic; Female; Fibroblast Growth Factor-23; Fibroblast Growth Factors; Glucuronidase; Immunohistochemistry; Isoenzymes; Klotho Proteins; Male; Mice; Mice, Knockout; Mice, Transgenic; Osteomalacia; Parathyroid Hormone; Phenotype; Phosphorus; Tartrate-Resistant Acid Phosphatase

Serum tartrate-resistant acid phosphatase 5b (TRACP) is a new marker of potential clinical use to monitor osteoclastic activity and bone resorption rate. The relationship between histomorphometric parameters of bone resorption and serum TRACP was evaluated in 14 chronically dialyzed patients and 6 healthy control subjects.. All patients underwent bone biopsies and serum biochemical testing for TRACP, intact parathyroid hormone (iPTH), pyridinoline cross-linked telopeptide domain of type I collagen (ICTP), total calcium, phosphorus, and albumin, which were measured at the time of biopsy.. Bone histological examination showed predominant hyperparathyroid bone disease (HPT) in 6 patients, mixed uremic osteodystrophy in 3 patients, low-turnover osteomalacia in 1 patient, and adynamic bone disease in 4 patients. Mean TRACP activity was 3.25 +/- 0.59 U/L in control subjects. Median TRACP activity was significantly greater in patients with HPT (11.97 +/- 8.92 U/L) than those with other types of renal osteodystrophy (ROD; 2.17 +/- 0.61 U/L). Serum iPTH levels were greatest in all patients with HPT, but also were significantly elevated in 7 of 8 patients with other types of ROD. Serum ICTP levels also were significantly elevated in all patients with HPT and 6 of 8 patients with other types of ROD. Serum TRACP levels correlated more strongly with histological parameters of osteoclasts than those of erosion. Also, correlations between TRACP and histological parameters of osteoclasts were stronger than those of iPTH and ICTP levels.. These early results suggest that serum TRACP levels correlate well with histological indices of osteoclasts and may serve as a specific marker for osteoclastic activity in patients with renal bone disease.

Topics: Acid Phosphatase; Bone and Bones; Bone Resorption; Chronic Kidney Disease-Mineral and Bone Disorder; Female; Humans; Isoenzymes; Osteomalacia; Renal Dialysis; Tartrate-Resistant Acid Phosphatase; Uremia

The aim of the present study was to clarify the therapeutic effects of 1alpha, 25[OH]2 vitamin D3 (calcitriol) pulse injection on bone lesions induced in a rat model of chronic cadmium toxicosis. Ovariectomized (OVX) and control-operated (sham-OVX) rats were given repeated intravenous injections of 0.5 mg/kg/day CdCl2 for 70 weeks. The rats were then treated intravenously with 0.02 microg/kg/day calcitriol 3 days per week for 8 weeks. CdCl2 treatment induced increases in osteoid volumes of the femur cortex and trabecula. This change was accompanied by an increase in the volume of iron deposition at the mineralization front of the trabeculae and a reduction in mineral density. Abnormalities of bone metabolic parameters, which were increases in the blood calcium, inorganic phosphorous, bone-specific alkaline phosphatase, parathyroid hormone (PTH) and osteocalcin levels, and in the urine deoxypyridinoline (D-PYR) level, were also induced. Calcitriol treatment increased the blood calcium and inorganic phosphorous levels, and reduced the blood PTH level. Decreases in blood tartrate-resistant acid phosphatase and urine d-PYR levels were also induced indicating that bone resorption was suppressed. The findings indicated that the increased osteoid volume of the cortex and Fe-deposition volume of the trabecula were improved. These effects or improvements were observed in the sham-OVX rats but not in the OVX rats.

Topics: Acid Phosphatase; Alkaline Phosphatase; Amino Acids; Analysis of Variance; Animals; Biomarkers; Bone and Bones; Bone Density; Cadmium; Cadmium Chloride; Cadmium Poisoning; Calcitriol; Chronic Disease; Erythrocyte Indices; Female; Femur; Hemoglobins; Iron; Models, Animal; Osteocalcin; Osteomalacia; Ovariectomy; Pulse Therapy, Drug; Rats; Rats, Sprague-Dawley

The study was carried out to evaluate the clinical validity and usefulness of serum tartrate-resistant acid phosphatase (TRAP) activity determined using an improved spectrophotometric assay. Enzyme activity was measured in 84 normal subjects and in 109 patients with common metabolic bone diseases. Mean values of serum TRAP activity in male subjects (n = 19; 10.4 +/- 2.15 U l-1) were not significantly different from those found in female subjects (n = 65; 10.8 +/- 1.8 U l-1). In the latter group mean values were significantly raised in post-menopausal subjects (10.5 +/- 2.0 U l-1; p less than 0.01) compared with mean values in pre-menopausal women (8.45 +/- 1.8 U l-1). We found a significant inverse correlation between serum TRAP activity values and bone mineral density (BMD) measured both at an ultradistal radial point (n = 33, r = -0.506; p less than 0.01), and at the lumbar spine (n = 57, r = -0.261; p less than 0.05). Mean serum TRAP activity values in patients with metabolic bone diseases were: primary hyperparathyroidism, n = 30: 14.2 +/- 4.89 U l-1, p less than 0.001 vs normal subjects; chronic maintenance haemodialysis, n = 19: 17.4 +/- 6.7, p less than 0.001; metastatic cancer, n = 13: 21.2 +/- 6.3, p less than 0.001; post-surgical hypoparathyroidism, n = 10: 9.9 +/- 1.8, NS; involutional osteoporosis, n = 20: 12.5 +/- 2.3 p less than 0.001; Paget's disease, n = 10: 16.8 +/- 3.5, p less than 0.001; osteomalacia, n = 7: 19.5 +/- 3.31, p less than 0.001.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Acid Phosphatase; Adult; Aging; Bone Density; Bone Diseases, Metabolic; Bone Remodeling; Female; Humans; Hyperparathyroidism; Male; Menopause; Middle Aged; Osteitis Deformans; Osteomalacia; Osteoporosis; Osteoporosis, Postmenopausal; Spectrophotometry; Tartrates

To evaluate the effects of calcitriol (1,25-dihydroxyvitamin D3) therapy for the bone disease induced by long-term treatment with anticonvulsants, we reviewed the medical records of 330 institutionalized oligophrenic children and young adults under 26 years of age to identify the 144 children who required anticonvulsant therapy. Of this latter group, 52 children were found to have serum alkaline phosphatase levels elevated more than 2 SDs above normal and were enrolled into this prospective three-year study. To achieve rapid resolution of the bone disease, we elected to use calcitriol at 0.25 to 0.75 micrograms/d. After 1195 patient-months of treatment, our data suggest that the dystrophic process was reversed in 42.3% of the cases, as judged by decreases in serum alkaline phosphatase levels at six months, 65.4% of cases at 12 months, and 83.3% of cases at 13 to 18 months. By 30 months of follow-up, all patients showed significant lowering of serum alkaline phosphatase levels. The improvements were slow and gradual. Twenty-six patients in the treatment series of 52 patients initially showed signs of rickets or osteomalacia on roentgenograms of the wrists. Of these 26 patients, 12 (46%) showed improvement on roentgenograms within 24 months of the beginning of treatment. With reference to complications, hypercalcemia (calcium level, greater than 11 mg/dL [2.74 mmol/L]) was encountered at the rate of one episode per 44 patient-months of treatment. Our results strongly suggest that calcitriol is effective in healing anticonvulsant-related osteomalacia among children and youths, with a low incidence of complications.

Topics: Acid Phosphatase; Adult; Anticonvulsants; Aspartate Aminotransferases; Calcitriol; Calcium; Child; Child, Preschool; Female; Humans; Hypercalcemia; Intellectual Disability; Male; Osteomalacia; Phosphates; Prospective Studies; Radiography; Rickets

A case of hypophosphataemic osteomalacia occurring in association with a carcinoma of prostate is described. Although only palliative treatment to the primary tumour was possible, worthwhile remission of bone symptoms, due to osteomalacia, was achieved with pharmacological doses of vitamin D. The presence of extensive skeletal metastases modified the radiological features of osteomalacia. Major alterations in the distribution of calcium within the skeleton were observed during a period when total body calcium remained unaltered. This observation may be of relevance to other cases in which osteosclerotic metastases develop.

Topics: Acid Phosphatase; Aged; Body Weight; Bone and Bones; Bone Neoplasms; Calcium; Carcinoma; Ergocalciferols; Humans; Male; Neoplasm Metastasis; Osteomalacia; Prostatic Neoplasms; Radiography; Vitamin D