scholarly journals Association of inorganic pyrophosphatase activity with normal calcification of rat costal cartilage in vivo

1969 ◽  
Vol 112 (4) ◽  
pp. 505-510 ◽  
Author(s):  
Nancy W. Alcock ◽  
Maurice E. Shils
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Inorganic Phosphate ◽  
Costal Cartilage ◽  
Hydrolytic Activity ◽  
Inorganic Pyrophosphatase ◽  
Inorganic Pyrophosphate ◽  
Pyrophosphatase Activity

1. Dialysed extracts of rat costal cartilage were shown to possess an enzyme that hydrolyses inorganic pyrophosphate. 2. Inorganic pyrophosphatase activity assayed in the presence of 2mm substrate was maximal at pH6·8. 3. Mg2+ was essential for activity, which was greatest with 10mm or higher concentrations of Mg2+. 4. Extracts prepared from cartilage taken from suckling rats (<20g.) showed little or no hydrolytic activity, but as rat weight increased inorganic pyrophosphatase activity was detected, increased to a maximum in tissue from animals weighing about 40g., and then rapidly declined. 5. The increase in inorganic pyrophosphatase activity was associated with an increase in the uptake of 45Ca by the cartilage in vivo. 6. Accumulation of calcium, inorganic phosphate and magnesium occurred when inorganic pyrophosphatase activity was at its maximum. 7. Alkaline phosphatase activity, measured in the same extracts used to determine pyrophosphatase activity, was highest in the tissues of the animals weighing <20g., and decreased as inorganic pyrophosphatase activity increased to its maximum. 8. There was no direct relationship between alkaline phosphatase activity and the onset of calcification.

scholarly journals Alkaline inorganic pyrophosphatase activity of mammalian-cell alkaline phosphatase

1967 ◽  
Vol 105 (1) ◽  
pp. 155-161 ◽  
Author(s):  
Rody P. Cox ◽  
Paul Gilbert ◽  
Martin J. Griffin
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Mammalian Cell ◽  
Cell Cultures ◽  
Alkaline Phosphatase Activity ◽  
Inorganic Pyrophosphatase ◽  
Mammalian Cell Cultures ◽  
Single Protein ◽  
Pyrophosphatase Activity ◽  
Substrate Induction

Alkaline phosphatase prepared from mammalian cell cultures was found to have alkaline inorganic pyrophosphatase activity. Both of these activities appear to be associated with a single protein, as demonstrated by: (1) concomitant purification of alkaline phosphatase and alkaline inorganic pyrophosphatase; (2) proportional precipitation of alkaline phosphatase and inorganic pyrophosphatase activities by titrating constant amounts of an enzyme preparation with increasing concentration of antibody; (3) immune electrophoresis, which showed that precipitin bands that have alkaline phosphatase activity also have pyrophosphatase activity; (4) inhibition of pyrophosphatase activity by cysteine, an inhibitor of alkaline phosphatase activity; (5) similar subcellular localization of the two enzyme activities as demonstrated by histochemical methods; (6) hormonal and substrate induction of alkaline phosphatase activity in mammalian cell cultures, which produced a nearly parallel rise in inorganic pyrophosphatase activity.

scholarly journals Problems inherent in obtaining the alkaline phosphatase reaction.

1980 ◽  
Vol 28 (1) ◽  
pp. 66-68 ◽  
Author(s):  
S B Doty
Keyword(s):  
Electron Microscopy ◽  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Enzyme Inhibitors ◽  
Light And Electron Microscopy ◽  
Histochemical Localization ◽  
Inorganic Pyrophosphatase ◽  
Pyrophosphatase Activity ◽  
Alkaline Phosphatase Reaction

Problems encountered in the histochemical localization of alkaline phosphatase activity are discussed and solutions presented. The purpose is to achieve a reaction that can be studied by light and electron microscopy and to distinguish alkaline glycerophosphatase from inorganic pyrophosphatase activity. Details are presented concerning fixatives, fixation times, incubation media, enzyme inhibitors, activators, and associated techniques that can be used to obtain optimal histochemical results.

scholarly journals A biodegradable porous composite scaffold of PCL/BCP containing Ang-(1-7) for bone tissue engineering

Cerâmica ◽  
2012 ◽  
Vol 58 (348) ◽  
pp. 481-488 ◽  
Author(s):  
F. A. Macedo ◽  
E. H. M. Nunes ◽  
W. L. Vasconcelos ◽  
R. A. Santos ◽  
R. D. Sinisterra ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Composite Scaffold ◽  
Weight Ratio ◽  
High Porosity ◽  
X Rays ◽  
Solvent Casting

Highly porous three-dimensional biodegradable scaffolds was obtained from beta-tricalcium phosphate-hydroxyapatite bioceramic (BCP), PCL, and Angiotensin-(1-7). We used the solvent casting and particulate leaching methods (SC/PL). The processed scaffolds were characterized by X-ray microtomography (µ-CT). Biocompatibility tests in vitro were performed during three and seven days using MTT and Alkaline Phosphatase Activity (APA) assays. Both the MTT activity and APA were evaluated using a one-way ANOVA test. The µ-CT results showed that the increase of the PCL:BCP weight ratio leads to structures with lower pore sizes. The pore interconnectivity of the processed scaffolds was evaluated in terms of the fragmentation index (FI). We observed that the obtained composites present poorly connected structures, with close values of FI. However, as the polymer phase is almost transparent to the X-rays, it was not taken into consideration in the µ-CT tests. The MTT activity assay revealed that scaffolds obtained with and without Angiotensin-(1-7) present mild and moderate cytotoxic effects, respectively. The APA assay showed that the rat osteoblasts, when in contact for three days with the PCL composites, presented an APA similar to that observed for the control cells. Nevertheless, for an incubation time of seven days we observed a remarkable decrease in the alkaline phosphatase activity. In conclusion, using the solvent casting and salt leaching method we obtained 3D porous that are composites of PCL, BC and Ang-(1-7), which have suitable shapes for the bone defects, a high porosity and interconnect pores. Furthermore, the viability in vitro showed that the scaffolds have potential for drug delivery system and could be used in future in vivo tests.

scholarly journals Simultaneous autoradiographic and histochemical analysis of bone formed in vitro.

1986 ◽  
Vol 34 (6) ◽  
pp. 769-773 ◽  
Author(s):  
H C Tenenbaum ◽  
C A McCulloch ◽  
K Palangio
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Time Course ◽  
Bone Cell ◽  
Histochemical Demonstration ◽  
Thymidine Uptake ◽  
Kinetics In Vivo

The simultaneous histochemical demonstration of alkaline phosphatase activity and autoradiographic demonstration of [3H]-thymidine uptake is valuable for study of bone cell kinetics in vivo or in vitro. By use of this technique, it has been possible to detect changes induced by a single dose of dexamethasone (10(-7) M) in the time course of alkaline phosphatase activity, the number of alkaline phosphatase-positive cells, and [3H]-thymidine labeling in bone formed in vitro.

scholarly journals Plasma Inorganic Pyrophosphate Deficiency Links Multiparity to Cardiovascular Disease Risk

2020 ◽  
Vol 8 ◽  
Author(s):  
Almudena Veiga-Lopez ◽  
Visalakshi Sethuraman ◽  
Nastassia Navasiolava ◽  
Barbara Makela ◽  
Isoken Olomu ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Vascular Calcification ◽  
Alkaline Phosphatase Activity ◽  
Disease Risk ◽  
Cardiovascular Disease Risk ◽  
Inorganic Pyrophosphate ◽  
Ectopic Mineralization ◽  
In Pregnancy

Epidemiological studies indicate that elevated alkaline phosphatase activity is associated with increased cardiovascular disease risk. Other epidemiological data demonstrate that mothers giving multiple childbirths (multipara) are also at increased risk of developing late-onset cardiovascular disease. We hypothesized that these two associations stem from a common cause, the insufficient plasma level of the ectopic mineralization inhibitor inorganic pyrophosphate, which is a substrate of alkaline phosphatase. As alkaline phosphatase activity is elevated in pregnancy, we hypothesized that pyrophosphate concentrations decrease gestationally, potentially leading to increased maternal vascular calcification and cardiovascular disease risk in multipara. We investigated plasma pyrophosphate kinetics pre- and postpartum in sheep and at term in humans and demonstrated its shortage in pregnancy, mirroring alkaline phosphatase activity. Next, we tested whether multiparity is associated with increased vascular calcification in pseudoxanthoma elasticum patients, characterized by low intrinsic plasma pyrophosphate levels. We demonstrated that these patients had increased vascular calcification when they give birth multiple times. We propose that transient shortages of pyrophosphate during repeated pregnancies might contribute to vascular calcification and multiparity-associated cardiovascular disease risk threatening hundreds of millions of healthy women worldwide. Future trials are needed to assess if gestational pyrophosphate supplementation might be a suitable prophylactic treatment to mitigate maternal cardiovascular disease risk in multiparous women.

Studies on Leukocyte Phosphatases

1971 ◽  
Vol 17 (3) ◽  
pp. 210-213 ◽  
Author(s):  
Lawrence R DeChatelet ◽  
James V Volk ◽  
Charles E McCall ◽  
M Robert Cooper
Keyword(s):  
Amino Acids ◽  
Alkaline Phosphatase ◽  
Enzyme Activity ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Leukocyte Alkaline Phosphatase ◽  
Complete Reversal

Abstract The activity of leukocyte alkaline phosphatase is inhibited by a number of amino acids, most notably cysteine and histidine. The mechanism of this inhibition involves chelation of Zn2+ by the amino acids, as indicated by the complete reversal of the inhibition by added Zn2+. The concentrations of amino acids and Zn2+ required to affect the enzyme activity are such that their interaction might represent an in vivo mechanism for the control of leukocyte alkaline phosphatase activity.

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