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.

scholarly journals Increase in alkaline phosphatase activity in calvaria cells cultured with diphosphonates

1979 ◽  
Vol 183 (1) ◽  
pp. 73-81 ◽  
Author(s):  
R Felix ◽  
H Fleisch
Keyword(s):  
Alkaline Phosphatase ◽  
Protein Synthesis ◽  
Enzyme Activity ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Heat Inactivation ◽  
High Concentration ◽  
Control Value ◽  
Km Value ◽  
Inhibitor Of Protein Synthesis

1. Dichloromethanediphosphonate and to a lesser degree 1-hydroxyethane-1,1-diphosphonate, two compounds characterized by a P-C-P bond, increased the alkaline phosphatase activity of cultured rat calvaria cells up to 30 times in a dose-dependent fashion. 2. Both diphosphonates also slightly inhibited the protein synthesis in these cells. 3. Thymidine, an inhibitor of cell division, did not inhibit the induction of the enzyme, indicating that the increase in enzyme activity was not due to the formation of a specific population of cells with high alkaline phosphatase activity. 4. The effect on alkaline phosphatase was suppressed by the addition of cycloheximide, an inhibitor of protein synthesis. 5. After subculturing the stimulated cells in medium without diphosphonates, the enzyme activity fell almost to the control value. 6. Bovine parathyrin diminished the enzyme activity of the control cells and the cells treated with dichloromethanediphosphonate; however, at high concentration the effect of parathyrin was greater on the diphosphonate-treated cells than on the control cells. 7. The electrophoretic behaviour, heat inactivation, inhibition by bromotetramisole or by phenylalanine, and the Km value of the induced enzyme were identical with that of the control enzyme.

scholarly journals Endocrine Relationships of Leukocyte Alkaline Phosphatase

Blood ◽  
1965 ◽  
Vol 25 (3) ◽  
pp. 356-369 ◽  
Author(s):  
FRED ROSNER ◽  
STANLEY L. LEE
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Mean Value ◽  
Conclusive Evidence ◽  
In Vitro Tests ◽  
Enzyme Release ◽  
Men And Women ◽  
Leukocyte Alkaline Phosphatase

Abstract Leukocyte alkaline phosphatase activity has been noted to be different in men and women. The mean leukocyte alkaline phosphatase activity for 74 normal men, aged 19 to 60 years, was 23 mg. of phosphorus per 1010 polvmorphonuclear leukocytes per hour. The corresponding mean value for 75 normal young women, age 19-48 years, was 35 (p < .001). No significant differences between boys and girls occurred until the time of puberty. After the menopause, the values for women approached the values for men. Women treated with androgens had lower leukocyte alkaline phosphatase activity than did control women. These results suggest that androgenic hormones inhibit this enzyme, and that other, as yet undefined endocrine influences, also affect its level of activity. In vitro tests with various concentrations of androgens and estrogens failed to provide conclusive evidence of direct effect on leukocytes although some degree of direct inhibition by androgens was suggested. Studies using saponin to effect enzyme release from leukocyte granules did not demonstrate whether the differences between men and women are differences of enzyme release or of content of leukocyte alkaline phosphatase.

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.

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