Showing papers on "Tartrate-resistant acid phosphatase published in 1988"

Inhibitory effect of a marine-sponge toxin, okadaic acid, on protein phosphatases. Specificity and kinetics

Abstract: The inhibitory effect of a marine-sponge toxin, okadaic acid, was examined on type 1, type 2A, type 2B and type 2C protein phosphatases as well as on a polycation-modulated (PCM) phosphatase. Of the protein phosphatases examined, the catalytic subunit of type 2A phosphatase from rabbit skeletal muscle was most potently inhibited. For the phosphorylated myosin light-chain (PMLC) phosphatase activity of the enzyme, the concentration of okadaic acid required to obtain 50% inhibition (ID50) was about 1 nM. The PMLC phosphatase activities of type 1 and PCM phosphatase were also strongly inhibited (ID50 0.1-0.5 microM). The PMCL phosphatase activity of type 2B phosphatase (calcineurin) was inhibited to a lesser extent (ID50 4-5 microM). Similar results were obtained for the phosphorylase a phosphatase activity of type 1 and PCM phosphatases and for the p-nitrophenyl phosphate phosphatase activity of calcineurin. The following phosphatases were not affected by up to 10 microM-okadaic acid: type 2C phosphatase, phosphotyrosyl phosphatase, inositol 1,4,5-trisphosphate phosphatase, acid phosphatases and alkaline phosphatases. Thus okadaic acid had a relatively high specificity for type 2A, type 1 and PCM phosphatases. Kinetic studies showed that okadaic acid acts as a non-competitive or mixed inhibitor on the okadaic acid-sensitive enzymes.

Induction of Calcitonin Receptors by lα, 25- Dihydroxyvitamin D3 in Osteoclast-Like Multinucleated Cells Formed from Mouse Bone Marrow Cells*

Abstract: We have developed a mouse marrow culture system, in which multinucleated cells (MNCs) are formed within 6-8 days. These MNCs showed several characteristics of osteoclasts, including tartrate-resistant acid phosphatase (TRACP) and the ability to resorb calcified dentine. lα,25-Dihydroxyvitamin D3 [lα,25(OH)2D3] stimulated the formation of TRACPpositive MNCs, and salmon calcitonin (CT) inhibited it. In this study, we examined whether the TRACP-positive MNCs formed from mouse marrow cells possess CT receptors, another typical characteristic of osteoclasts. Mouse marrow cells cultured for 8 days with 10 nM lα,25(OH)2D3 and freshly isolated authentic mouse osteoclasts were incubated with [125I]-salmon CT in the presence or absence of excess amounts of unlabeled CT, stained for TRACP, and processed for autoradiography. The [125I]-CT exclusively bound to TRACP-positive mononuclear cells and MNCs formed in the lα,25(OH)2D3-treated cultures and also to isolated mouse osteoclasts. Both [125I]-CT binding and TRACP a...

Tartrate-resistant acid phosphatase activity in rat osteoblasts and osteocytes

Abstract: Tartrate-resistant acid phosphatase activity, generally known as a distinctive cytochemical feature of osteoclasts, has been demonstrated in osteoblasts and osteocytes in low-temperature glycol methacrylate-embedded rat bone specimens.

Chick osteoblasts contain fluoride-sensitive acid phosphatase activity.

Abstract: We used histological and biochemical methods to determine the cellular origin of bone matrix fluoride-sensitive acid phosphatase in chicken bone. Embryonic chicken calvariae were embedded in plastic and sections stained for acid phosphatase at various concentrations of substrate and fluoride. Acid phosphatase activity was observed in osteoblasts and osteoclasts but not in fibroblasts. Striking inhibition of osteoblastic acid phosphatase occurred at 100 microM fluoride, a concentration that had no apparent effect on osteoclastic acid phosphatase. Inhibition of osteoblastic and osteoclastic acid phosphatase by fluoride was also examined using extracts of embryonic chicken calvarial cells, mouse osteoblasts (MC3T3-El cell line), and purified chick osteoclasts, respectively. Fluoride is a partial competitive inhibitor of both chicken and mouse osteoblastic acid phosphatases, with apparent inhibition constants of 10-100 microM. These concentrations of fluoride correspond to those that increase bone formation i...

Diminished activity of tartrate resistant acid phosphatase in alveolar macrophages from patients with active sarcoidosis.

Abstract: Alveolar macrophages differ from their percursors in blood, monocytes, by expressing strong activity of the tartrate resistant variant of acid phosphatase (TAcP). A study was carried out to analyse the expression of this enzyme cytochemical marker by alveolar macrophages from bronchoalveolar lavage cells from 34 patients with sarcoidosis and 12 control subjects. Alveolar macrophages from control subjects displayed a strong and homogeneous staining pattern and only 0.1% of cells were negative after staining. Macrophages from patients with sarcoidosis showed reduced TAcP activity and up to 7% of the cells were negative. The percentage of TAcP negative macrophages was correlated with the percentage of lymphocytes and with the ratio of CD4 to CD8 lymphocytes among cells recovered by bronchoalveolar lavage. The reduced TAcP activity in alveolar macrophages from patients with sarcoidosis may be due to an increased recruitment of immature precursors from blood.

Tartrate-resistant acid phosphatase containing cells in nodular fasciitis, proliferative fasciitis, and proliferative myositis.

Abstract: Five cases of nodular fasciitis, three cases of proliferative fasciitis, and one case of proliferative myositis were investigated by tartrate-resistant acid phosphatase (TRAP) histochemistry on conventional paraffin-embedded material. In all cases varying numbers of enzyme-positive cells were detected. Cytological investigations revealed the presence of small round cells, elongated spindle cells, medium-sized mono- or binucleated cells, and multinuclear giant cells, the latter resembling osteoclasts. However, the typical ganglion-like cells were TRAP-negative in almost all tests. The TRAP-pattern may help to differentiate nodular fasciitis and allied lesions from inflammatory pseudotumours or organising haematomas, as the latter do not contain TRAP-positive cells. As TRAP appears to be a marker for a special population of phagocytizing and non phagocytizing histiocytes, nodular fasciitis and its proliferative variants may be assumed to be fibrohistiocytic tumorous conditions.

Hypocalcemia response following calcitonin administration: Lack of correlation with osteoclast number determined after histoenzymologic identification in osteoprorosis

Abstract: The relationship between calcitonin-induced hypocalcemia and histomorphometric parameters of bone resorption was examined in iliac crest biopsies of 30 osteoporotic patients aged 55–86 years all of whom had received a single injection of 100 UI of salmon calcitonin. Number of osteoclasts and active resorption surfaces were determined after histoenzymologic staining based on osteoclastic tartrate resistant acid phosphatase content. No significant correlation could be demonstrated between the drop of hypocalcemia and the different histomorphometric parameters. It can be concluded that the calcitonin test is useless in osteoporosis.