Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.3.1 (alkaline phosphatase)
47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The conditions necessary for the secretion of phospholipase C (phosphatidylcholine cholinephosphohydrolase) by Pseudomonas aeruginosa were studied. Enzyme secretion by washed cell suspensions required a carbon source and ammonium, potassium, and calcium ions. The calcium requirement could be substituted by magnesium and strontium but not by copper, manganese, cobalt, or zinc. During growth in liquid medium, cells secreted phospholipase C during late logarithmic and early stationary phases. Secretion was repressed by the addition of inorganic phosphate but not by organic phosphates, glucose, or sodium succinate. Studies with tetracycline indicated that de novo protein synthesis was necessary for the secretion of phospholipase C and that the exoenzyme was not released from a preformed periplasmic pool. Similarly, extraction of actively secreting cells with 0.2 M MgCl2 at pH 8.4 solubilized large quantities of the periplasmic enzyme alkaline phosphatase but insignificant amounts of phospholipase C. Bacteria continued to secrete enzyme for nearly 45 min after the addition of inorganic phosphate or rifampin.
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PMID:Secretion of phospholipase C by Pseudomonas aeruginosa. 11 87

The intravenous application of 89-strontium for the relief of pain in 43 patients with breast cancer, bronchogenic cancer, carcinoma of the prostate, hypernephroma and lymphoma with generalized bone metastases is reported. A remarkable clinical improvement was achieved in 33 (76.7%) patients. In four patients a transient analgesic effect was observed. In six cases no response could be achieved. The therapeutic effect usually was long-lasting. At the same time, an increase of alkaline phosphatase was observed, which was interpreted as an indication for the stimulation of osteoblasts and osteoid peripheral zones owing to beta-emission of the radioisotope in the affected areas. There was a significant correlation between the concentration of 85Sr in the bone scan and the therapeutic result of 89Sr-therapy. The indication for such therapy and possible late adverse effects of bone-seeking isotopes are discussed.
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PMID:[Endo-osseous isotope therapy of malignant skeletal disease (author's transl)]. 14 38

The hydrolysis of disodium p-nitrophenyl phosphate at pH 9.0 by slices of formaldehydee-fixed rat renal cortex was investigated by colorimetric estimation of the nitrophenol liberated. It was found that three types of activity could be identified on the basis of their responses to inhibitors and cations: (a) alkaline phosphatase sensitive to inhibition by L-tetramisole; (b) potassium-dependent phosphatase, probably identifiable with the phosphatase component of sodium-potassium-dependent transport adenosine triphosphatase (?Na-K-ATPase); and (c) alkaline phosphatase insensitive to L-tetramisole. It was found that in the presence of strontium ions, as used in Na-K-ATPase cytochemistry, the activities of the second and third types of enzyme were approximately equal. The implications of these findings for the cytochemical demonstration of Na-K-ATPase are discussed.
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PMID:The significance of inhibitor-resistant alkaline phosphatase in the cytochemical demonstration of transport adenosine triphosphatase. 16 3

Potassium-stimulated p-nitrophenylphosphatase (K+-pNPPase) activity was investigated in rat somatosensory cortex where 64-88% of enzymatic activity survived 5-10 min of fixation with 3% formaldehyde in 0.1 M cacodylate buffer, pH 7.4. Potassium-stimulated activity was inhibited by 1-10 mM ouabain. Levamisole (1.7 mM) inhibited brain alkaline phosphatase activity, facilitating the detection of K+-pNPPase activity. Strontium (10-20 mM) inhibited enzymatic activity by 38-75%. In parallel histochemical studies reaction product was found in strata, with cortical layers 2, 3, 4 and the outer portion of 5 containing the heaviest deposits. Highly reactive, vertically oriented, large diameter fibers were seen as groups between the outer portion of layer 5 and the pail surface. These fibers apparently arborize in the superficial layers. Smaller fibers were also positive and were oriented in various planes. The highest density of smaller, positive fibers occurred in layers 2 through 5. All positive fibers appeared to be axons or dendrites. Reaction product was not heavily concentrated in neuron perikarya or in glial elements. Sections did not contain reaction product when incubated in media lacking K+ or containing ouabain. The convergence of data from parallel histochemical and biochemical approaches supports the conclusion that the reactivity localized in the cerebral cortex represented the site of K+-pNPPase, a known component of the Na+,K+-adenosine triphosphatase complex. Neuronal processes demonstrated the highest enzymatic activity and may be most important in the active transport of Na+ and K+ in somatosensory cortex.
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PMID:Histochemical localization of potassium-stimulated P-nitrophenylphosphatase activity in the somatosensory cortex of the rat. 18 89

A method for the synthesis of an analog of vitamin D3--1alpha-hydroxy vitamin D3 (1alpha-OH D3) from cholesta-4,6-dien-3beta-ol was developed. Biological activity of this compound in the chick organism was measured. The growth stimulating effect of 1alpha-OH D3 and its effect on bone tissue mineralization and serum biochemical parameters (content of calcium, inorganic phosphorus and activity of alkaline phosphatase) were 4--5 times higher than those of vitamin D3 in low doses (19.5--39 pmole/day). In chicks given 1alpha-OH D3 at doses of 39--195 pmole/day most biochemical parameters reached plateau typical of chicks adequately provided with vitamin D. A peculiar feature of 1alpha-OH D3 was a rapid response of the chick organism to/low doses. As early as one hour after intramuscular injection of 650 pmole of 1alpha-OH D3 to D-avitaminotic chicks, the content of calcium-bound protein in the intestinal mucosa and active transport of calcium ions in the inverted intestinal sac increased drastically. It was demonstrated that 1alpha-OH D3 showed antirachitic action, when the physiological reaction to vitamin D3 was inhibited by dietary strontium.
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PMID:[1 alpha-hydroxyvitamin D3: chemical synthesis and biological effect]. 20 64

The distribution and properties of cytochemically demonstrable phosphatases in the near-term guinea-pig placenta were examined using a strontium capture technique for sodium- and potassium-dependent adenosine triphosphatase (Na+, K+-ATPase) and a lead capture technique for magnesium-dependent adenosine triphosphatase (Mg2+-ATPase). Localizations with the strontium technique in the presence of an alkaline phosphatase inhibitor were mainly on the syncytiotrophoblast plasma membranes; the reaction was potassium-dependent and ouabain-sensitive. Reaction product using the lead capture method was found on both trophoblast and endothelial cell plasma membranes and was independent of magnesium and insensitive to p-hydroxymercuribenzoate (POHMB), an inhibitor of membrane ATPases. However, a very large proportion of this reaction could be blocked by an alkaline phosphatase inhibitor. It is concluded that the strontium capture technique gave a reliable localization for Na+, K+-ATPase. However, the lead capture method mainly demonstrated alkaline phosphatase, and does not offer a useful approach to specific ATPase studies in this particular system.
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PMID:The localization and properties of membrane adenosine triphosphatases in the guinea-pig placenta. 22 15

Tests conducted on albino rats of the Wistar line demonstrated that introduction of large doses of ergocalciferol (vitamin D2) to animals kept on a strontium-rich diet exhibiting signs of rickets brings about the development in them of specific manifestations of the D-vitamin activity, viz. rising level of calcium, strontium and inorganic phosphorus in the blood serum, lowering of the alkaline phosphatase activity and a greater degree of the soft tissues calcification.
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PMID:[Toxic action of ergocalciferol in strontium rickets]. 30 27

Extracts of the calcinogenic plants Solanum malocoxylon and Cestrum diurnum stimulate phosphate absorption by the jejunum of vitamin D-deficient chicks, as determined by everted gut sac technique. Their action on cellular pathways of transepithelial phosphate transport is indistinguishable thereby from that of cholecalciferol. Increased net absorption from the lumen was due to enhanced uptake of phosphate from the luminal side, while leakage of tissue phosphate in the opposite direction was apparently unaffected. Steep serosa/mucosa concentration gradients were observed as consequence of enhanced levels of transepithelial phosphate flux in the mucosa-to-serosa direction. With respect to their stimulatory action on phosphate absorption, the calcinogenic plant factors retained their biological activity when phosphate transport was depressed by a high strontium diet. Their action in overcoming the strontium inhibition of phosphate absorption, calcium-binding protein synthesis, and alkaline phosphatase activity, was comparable to the effect of 1,25-dihydroxycholecalciferol. On the basis of these biological responses, the action of the plant factors from Solanum malacoxylon and Cestrum diurnum provides further evidence for their close resemblance to the hormonally active sterol.
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PMID:Stimulatory effect of 1,25-dihydroxycholecalciferol-like substances from Solanum malacoxylon and Cestrum diurnum on phosphate transport in chick jejunum. 70 9

Strontium-89 has been used for the treatment of painful bony metastases in patients suffering from disseminated adenocarcinoma of the prostate, with a variable proportion of patients obtaining clinically significant reductions in analgesic requirements. Based on data revealing enhancement of continuous low-dose rate irradiation by low-dose cisplatin in murine models, a protocol using 148 MBq (4 mCi) of 89Sr and 35 mg/m2 of cisplatin infused over 2 days, 1 and 4 wk after administration of the radioisotope was undertaken. Preliminary data suggest good pain relief with 55% of 18 patients entered thus far obtaining at least a 50% reduction in analgesic requirements. Improvements in total alkaline phosphatase and serum lactate dehydrogenase have consistently been seen, with some patients exhibiting improvements in hemoglobin, tumor markers and bone scans. Toxicity appears to be mild, with no life-threatening complications. In particular, myelosuppression after one course of treatment was modest, but retreatments in two patients has resulted in grade 3 hematologic toxicity. Two patients developed a "pain flare" after administration of cisplatin. Further accrual to this study will allow more accurate determination of pain response rate, and improved evaluation of parameters of objective response.
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PMID:Strontium-89 and low-dose infusion cisplatin for patients with hormone refractory prostate carcinoma metastatic to bone: a preliminary report. 163 33

Blacks are known to have a higher bone mass than whites and have recently been found to have significantly different levels of calcitropic hormones and other biochemical indices of calcium metabolism. To assess the possible significance of these biochemical differences to interracial differences in bone mass, we have undertaken an assessment of indices of calcium metabolism in Polynesian subjects, since they also have a higher bone mass than whites. Serum concentrations of 25-hydroxyvitamin D were slightly lower in Polynesians than in whites (65 +/- 5 vs. 95 +/- 10 nmol/L; P less than 0.02), but there were no differences between the groups in serum levels of calcium (total and ionized), phosphate, magnesium, 1,25-dihydroxyvitamin D, PTH, calcitonin, alkaline phosphatase activity, and bone gla-protein. Furthermore, urinary excretion of hydroxyproline, calcium, phosphate, magnesium, sodium, and potassium and the tubular maximum for the reabsorption of phosphate were not different between whites and Polynesians. Intestinal strontium absorption was similar in the two groups. In contrast, distal forearm bone mineral content was higher in Polynesians (P less than 0.01) and midupper arm muscle area was also increased in this group (P less than 0.005). It is concluded that the higher bone mass of Polynesians cannot be attributed to alterations in the basal levels of calcitropic hormones, but may be related to their greater muscle mass. It is probable that the previously observed black-white differences in the vitamin D endocrine system are secondary to the effects of skin color on vitamin D synthesis and are not contributory to the lower bone mass of whites.
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PMID:Calcitropic hormone levels in polynesians: evidence against their role in interracial differences in bone mass. 233 80


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