The onset of phosphatase activity in early mammalian embryos

Development ◽  
1977 ◽  
Vol 42 (1) ◽  
pp. 305-308
Author(s):  
V. Ishiyama ◽  
L. Izquierdo

The onset of acid and alkaline phosphatase activity is determined by means of Burstone's azo dye coupling methods in oocytes and embryos of the mouse, rat and hamster, and in mouse embryos cultured in vitro. Acid phosphatase activity is detected in all cases while alkaline phosphatase activity begins during the 4-cell stage and is always present thereafter. The method is sensitive regarding detection of activity but does not permit the quantification nor a precise localization of the enzymes.

1968 ◽  
Vol 16 (11) ◽  
pp. 693-706 ◽  
Author(s):  
M. VAN DER PLOEG ◽  
P. VAN DUIJN

A model system consisting of polyacrylamide films into which cell sonicate is incorporated was applied to investigate quantitative aspects of the cytochemical azo dye coupling method for alkaline phosphatase activity in neutrophilic leukocytes. The films were assayed in media containing naphthol AS-MX phosphate and 4-aminodiphenylamine diazonium sulfate. Optimal reaction conditions under which proportionality existed between the amount of reaction product and incubation time or enzyme concentration were determined. Since the enzyme activity in the films could also be measured chemically, using disodium phenyl phosphate as a substrate, a direct relation between the cytochemical and biochemical activity could be established. The azo dye coupling method was applied for the quantification of the enzyme activity. Air-dried microscopic preparations of exudate neutrophils were stained and the amount of dye formed in the cytoplasm of individual leukocytes was measured with a cytospectrophotometer based on the two-wavelength principle. By reference to the relation between biochemical and cytochemical activities in the model films, the cytochemically determined enzyme activity could be expressed in biochemical units. Independently, the average alkaline phosphatase activity per cell was determined by direct biochemical assay of the leukocyte suspension. The results showed that about 60% of the biochemically assayed activity in sonicate was demonstrated in the cell preparations by the cytochemical staining method. The discrepancy between the results of the two methods is discussed. The applicability of the model system for elucidation of the relationship between the results of cytochemical and biochemical enzyme determination in cells is stressed.


Author(s):  
Kari Hanson ◽  
Carly Isder ◽  
Kristen Shogren ◽  
Anthony L. Mikula ◽  
Lichun Lu ◽  
...  

OBJECTIVE The use of intrawound vancomycin powder in spine surgery has been shown to decrease the rate of surgical site infections; however, the optimal dose is unknown. High-dose vancomycin inhibits osteoblast proliferation in vitro and may decrease the rate of solid arthrodesis. Bone marrow–derived mesenchymal stem cells (BMSCs) are multipotent cells that are a source of osteogenesis in spine fusions. The purpose of this study was to determine the effects of vancomycin on rat BMSC viability and differentiation in vitro. METHODS BMSCs were isolated from the femurs of immature female rats, cultured, and then split into two equal groups; half were treated to stimulate osteoblastic differentiation and half were not. Osteogenesis was stimulated by the addition of 50 µg/mL l-ascorbic acid, 10 mM β-glycerol phosphate, and 0.1 µM dexamethasone. Vancomycin was added to cell culture medium at concentrations of 0, 0.04, 0.4, or 4 mg/mL. Early differentiation was determined by alkaline phosphatase activity (4 days posttreatment) and late differentiation by alizarin red staining for mineralization (9 days posttreatment). Cell viability was determined at both the early and late time points by measurement of formazan colorimetric product. RESULTS Viability within the first 4 days decreased with high-dose vancomycin treatment, with cells receiving 4 mg/mL vancomycin having 40%–60% viability compared to the control. A gradual decrease in alizarin red staining and nodule formation was observed with increasing vancomycin doses. In the presence of the osteogenic factors, vancomycin did not have deleterious effects on alkaline phosphatase activity, whereas a trend toward reduced activity was seen in the absence of osteogenic factors when compared to osteogenically treated cells. CONCLUSIONS Vancomycin reduced BMSC viability and impaired late osteogenic differentiation with high-dose treatment. Therefore, the inhibitory effects of high-dose vancomycin on spinal fusion may result from both reduced BMSC viability and some impairment of osteogenic differentiation.


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