scholarly journals In vitro stimulation of alkaline phosphatase activity in immature embryonic chick pelvic cartilage by adenosine

1982 ◽  
Vol 93 (2) ◽  
pp. 338-342 ◽  
Author(s):  
WM Burch ◽  
HE Lebovitz
Keyword(s):  
Alkaline Phosphatase ◽  
Cyclic Amp ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Maximal Response ◽  
Embryonic Chick ◽  
In Ovo ◽  
Developmental Age ◽  
Stimulation Of

Cyclic AMP content in embryonic chick pelvic cartilage increases significantly as the embryo ages from 8 to 10 d. This in ovo elevation in cyclic AMP content precedes maximal cartilage alkaline phosphatase activity by some 24 h. We studied whether this temporal relationship may be causally related, using an in vitro organ culture. Incubation of pelvic cartilage from 9- and 10-d embryos in medium containing monobutyryl cyclic AMP (BtcAMP) resulted in significant increases in alkaline phosphatase activity (220 and 66 percent, respectively) as compared to that of cartilages incubated in medium alone. This stimulation was both concentration- and time-dependent with maximal response at 0.5 mM BtcAMP and 4-h incubation, respectively. Similar incubations of cartilage in medium containing 1-methyl-3-isobutyl xanthine (MIX), 0.25 mM, also resulted in increased alkaline phosphatase activity (114 percent). However, pelvic cartilage from 11-d embryos incubated in medium containing BtcAMP or MIX showed no increase in alkaline phosphatase activity. We postulated that developmental age was the factor responsible for this difference in response and that immature cartilage (that with little or no alkaline phosphatase activity) would respond to BtcAMP whereas mature cartilage (that with significant alkaline phosphatase activity) would not. This was tested by incubating end sections of 11-d cartilage, which have little alkaline phosphatase activity, and center sections, which have significantly alkaline phosphatase activity, with both BtcAMP and MIX. Alkaline phosphatase activity in end sections (immature cartilage) was stimulated by BtcAMP and MIX, whereas it was not stimulated in the center sections. Actinomycin D and cycloheximide inhibited BtcAMP and MIX stimulation of alkaline phosphatase activity. Thus, the in vitro data suggest that cyclic AMP is a mediator for the stimulation of alkaline phosphatase activity in embryonic cartilage.

The inhibitory effects of vancomycin on rat bone marrow–derived mesenchymal stem cell differentiation

2021 ◽  
pp. 1-5
Author(s):  
Kari Hanson ◽  
Carly Isder ◽  
Kristen Shogren ◽  
Anthony L. Mikula ◽  
Lichun Lu ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Alkaline Phosphatase ◽  
Osteogenic Differentiation ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
High Dose ◽  
Inhibitory Effects ◽  
Alizarin Red ◽  
Osteogenic Factors

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.

The influence of titanium surfaces treated by alkalis on macrophage and osteoblast-like cell adhesion and gene expression in vitro

RSC Advances ◽  
2015 ◽  
Vol 5 (99) ◽  
pp. 81378-81387 ◽  
Author(s):  
Ting Ma ◽  
Xi-Yuan Ge ◽  
Sheng-Nan Jia ◽  
Xi Jiang ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Alkaline Phosphatase ◽  
Cell Adhesion ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Related Gene ◽  
Titanium Surfaces

The effect of alkali-treated titanium surfaces on inflammation-related gene expression of macrophages and alkaline phosphatase activity of osteoblast-like cells.

Acidosis inhibits osteoblastic and stimulates osteoclastic activity in vitro

1992 ◽  
Vol 262 (3) ◽  
pp. F442-F448 ◽  
Author(s):  
N. S. Krieger ◽  
N. E. Sessler ◽  
D. A. Bushinsky
Keyword(s):  
Alkaline Phosphatase ◽  
Metabolic Acidosis ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Collagen Synthesis ◽  
Calcium Flux ◽  
Osteoclastic Activity ◽  
Glucuronidase Activity

Metabolic acidosis induces net calcium flux (JCa) from cultured neonatal mouse calvariae through physicochemical and cell-mediated mechanisms. To determine the role of osteoblasts in acid-induced JCa, collagen synthesis and alkaline phosphatase activity were assessed in calvariae incubated in reduced pH and bicarbonate medium, a model of metabolic acidosis (Met), and compared with controls (Ctl). Collagen synthesis fell from 30.5 +/- 1.1 in Ctl to 25.1 +/- 0.4% with Met, and alkaline phosphatase decreased from 403 +/- 25 in Ctl to 298 +/- 21 nmol Pi.min-1.mg protein-1 with Met. During acidosis JCa was correlated inversely with percent collagen synthesis (r = -0.743, n = 11, P = 0.009) and with alkaline phosphatase activity (r = -0.453, n = 22, P = 0.034). To determine the role of osteoclasts in acid-induced JCa, osteoclastic beta-glucuronidase activity was determined in Ctl and Met in the absence or presence of the osteoclastic inhibitor calcitonin (CT, 3 x 10(-9) M). Met increased beta-glucuronidase (5.9 +/- 0.2) compared with Ctl (4.6 +/- 0.3 micrograms phenolphthalein released.bone-1.h-1), whereas CT inhibited beta-glucuronidase in both Ctl and Met (3.1 +/- 0.2 and 3.5 +/- 0.3, respectively). During acidosis JCa was correlated directly with beta-glucuronidase activity (r = 0.683, n = 42, P less than 0.001). Thus the cell-mediated component of JCa during acidosis in vitro appears to result from a combination of inhibited osteoblastic and stimulated osteoclastic activity.

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