scholarly journals Biphasic Functions of Sodium Fluoride (NaF) in Soft and in Hard Periodontal Tissues

2022 ◽  
Vol 23 (2) ◽  
pp. 962
Author(s):  
Xingzhi Wang ◽  
Nitesh Tewari ◽  
Fuyuki Sato ◽  
Keiji Tanimoto ◽  
Lakshmi Thangavelu ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Sodium Fluoride ◽  
Clinical Applications ◽  
Fluoride Treatment ◽  
Periodontal Tissues ◽  
Low Concentrations ◽  
Different Tissues

Sodium fluoride (NaF) is widely used in clinical dentistry. However, the administration of high or low concentrations of NaF has various functions in different tissues. Understanding the mechanisms of the different effects of NaF will help to optimize its use in clinical applications. Studies of NaF and epithelial cells, osteoblasts, osteoclasts, and periodontal cells have suggested the significant roles of fluoride treatment. In this review, we summarize recent studies on the biphasic functions of NaF that are related to both soft and hard periodontal tissues, multiple diseases, and clinical dentistry.

Serum Cholinesterase Variants: Examination of Several Differential Inhibitors, Salts, and Buffers Used to Measure Enzyme Activity

1971 ◽  
Vol 17 (3) ◽  
pp. 183-191 ◽  
Author(s):  
Philip J Garry
Keyword(s):  
Enzyme Activity ◽  
Sodium Fluoride ◽  
Phosphate Buffer ◽  
Divalent Cations ◽  
Kinetic Studies ◽  
Competitive Inhibitor ◽  
Serum Cholinesterase ◽  
Low Concentrations

Abstract Dibucaine, used as a differential inhibitor with acetyl-, propionyl-, and butyrylthiocholine as substrate, clearly identified the "usual" and "atypical" serum cholinesterases. Succinylcholine was also used successfully as a differential inhibitor with butyrylthiocholine as substrate. Sodium fluoride, used as a differential inhibitor, gave conflicting results, depending on whether Tris or phosphate buffer was used in the assay. Mono- and divalent cations (NaCl, KCl, MgCl2, CaCl2, and BaCl2) activated the "usual" and inhibited the "atypical" enzyme at low concentrations. The "usual" enzyme had the same activity in 0.05 mol of Tris or phosphate buffer per liter, while the heterozygous and "atypical" enzymes showed 12 and 42% inhibition, respectively, when assayed in the phosphate buffer. Kinetic studies showed the phosphate acted as a competitive inhibitor of "atypical" enzyme. Km values, determined for "usual" and "atypical" enzymes, were 0.057 and 0.226 mmol/liter, respectively, with butyrylthiocholine as substrate.

Role of cell replication in regulation of Na-coupled hexose transport in LLC-PK1 epithelial cells

1986 ◽  
Vol 250 (2) ◽  
pp. C314-C318 ◽  
Author(s):  
A. Moran ◽  
J. S. Handler ◽  
M. Hagan
Keyword(s):  
Epithelial Cells ◽  
Ionizing Radiation ◽  
Thymidine Incorporation ◽  
Regulatory Process ◽  
Hexose Transport ◽  
Cell Replication ◽  
Response Data ◽  
Low Concentrations ◽  
High Concentrations

The glucose concentration in growth medium has been shown to regulate the number of sodium-coupled glucose transporters in LLC-PK1 epithelial cells. Epithelia grown in high concentrations of glucose express fewer transporters than epithelia grown in low concentrations of glucose. In the present work, the effect of a dose of ionizing radiation sufficient to block the incorporation of thymidine was examined in order to gauge the importance of cell replication in the hexose transport regulatory process. The low rate of thymidine incorporation in the plateau phase was completely eliminated by ionizing radiation. Under conditions of irradiation that completely blocked thymidine incorporation, down-regulation, namely the loss of alpha-methylglucoside-concentrating capacity, brought about by switching the epithelium from low to high glucose-containing medium, is independent of the irradiation and therefore most likely is also independent of cell replication. In contrast, the up-regulatory phenomenon is strongly impaired by radiation. This impairment may be due to specific radiation impairment of gene expression necessary for the up-regulatory process. It is apparent from the dose-response data that up-regulation is not inhibited by irradiation in a simple manner and is not inhibited at the same radiation dose as cell replication.

scholarly journals Library of Sequence-specific Radioimmunoassays for Human Chromogranin A

1999 ◽  
Vol 45 (4) ◽  
pp. 549-560 ◽  
Author(s):  
Tine Børglum Jensen ◽  
Linda Hilsted ◽  
Jens F Rehfeld
Keyword(s):  
Carcinoid Tumor ◽  
Neuroendocrine Tumors ◽  
Chromogranin A ◽  
Acidic Protein ◽  
Binding Affinities ◽  
Cleavage Sites ◽  
Tumor Patients ◽  
High Binding ◽  
Low Concentrations ◽  
Different Tissues

Abstract Background: Human chromogranin A (CgA) is an acidic protein widely expressed in neuroendocrine tissue and tumors. The extensive tissue- and tumor-specific cleavages of CgA at basic cleavage sites produce multiple peptides. Methods: We have developed a library of RIAs specific for different epitopes, including the NH2 and COOH termini and three sequences adjacent to dibasic sites in the remaining part of CgA. Results: The antisera raised against CgA(210–222) and CgA(340–348) required a free NH2 terminus for binding. All antisera displayed high titers, high indexes of heterogeneity (∼1.0), and high binding affinities (Keff0 ∼ 0.1 × 1012 to 1.0 × 1012 L/mol), implying that the RIAs were monospecific and sensitive. The concentration of CgA in different tissues varied with the assay used. Hence, in a carcinoid tumor the concentration varied from 0.5 to 34.0 nmol/g tissue depending on the specificity of the CgA assay. The lowest concentration in all tumors was measured with the assay specific for the NH2 terminus of CgA. This is consistent with the relatively low concentrations measured in plasma from carcinoid tumor patients by the N-terminal assay, whereas the assays using antisera raised against CgA(210–222) and CgA(340–348) measured increased concentrations. Conclusion: Only some CgA assays appear useful for diagnosis of neuroendocrine tumors, but the entire library is valuable for studies of the expression and processing of human CgA.

Tannin stimulates arachidonic acid release from bovine tracheal epithelial cells

1996 ◽  
Vol 270 (4) ◽  
pp. L613-L618
Author(s):  
M. M. Cloutier ◽  
L. Guernsey
Keyword(s):  
Arachidonic Acid ◽  
Epithelial Cells ◽  
Pertussis Toxin ◽  
Condensed Tannin ◽  
Tracheal Epithelial Cells ◽  
Low Concentrations ◽  
Tracheal Epithelial ◽  
Acid Release ◽  
High Concentrations ◽  
Dose Dependent

Condensed tannin, isolated from cotton bracts extract (CBE), increases arachidonic acid (AA) release from rabbit alveolar macrophages and inhibits its subsequent reacylation. We determined whether tannin from CBE had any effect upon AA release in bovine tracheal epithelial cells (BTE). [14C] AA release was measured at timed intervals after addition of various concentrations of tannin to BTE cells grown to confluence in the presence of [14C] AA. Tannin caused a time- and dose-dependent release of AA from airway cells, with a maximum release occurring at 1 min in the presence of 100 micrograms/ml of tannin, and was confirmed by high-pressure liquid chromatography. The pattern of release was similar to that observed with bradykinin (2 x 10(-6) M). AA release by tannin was partially inhibited by indomethacin (10(-5) M) but not by 5,8,11,14-eicosatetraynoic acid (ETYA; 10(-5) M. Both of these drugs were effective in inhibiting bradykinin-induced AA release. In addition, AA release was not inhibited by cycloheximide. Endotoxin at 100 pg/ml and higher also caused a time-dependent release of AA that was not inhibitable by indomethacin or ETYA. Tannin-induced AA release was inhibited by pretreatment with pertussis toxin but not by neomycin, an inhibitor of phospholipase C (PLC). Neither pertussis toxin nor neomycin had any effect upon endotoxin-induced AA release. In other experiments, neither tannin nor endotoxin had any effect on [14C]AA uptake by BTE. These data demonstrate that tannin at low concentrations and endotoxin at high concentrations increase AA release by BTE cells. The AA release by tannin is partially metabolized by the cyclooxygenase pathway. We hypothesize that tannin-induced AA release is not mediated by PLC but may be mediated by other phospholipases, including PLA2.

scholarly journals Interactions between neutral endopeptidase (EC 3.4.24.11) and the substance P (NK1) receptor expressed in mammalian cells

1994 ◽  
Vol 299 (3) ◽  
pp. 683-693 ◽  
Author(s):  
A Okamoto ◽  
M Lovett ◽  
D G Payan ◽  
N W Bunnett
Keyword(s):  
Substance P ◽  
Epithelial Cells ◽  
Mammalian Cells ◽  
Neutral Endopeptidase ◽  
Nk1 Receptor ◽  
Endopeptidase 24.11 ◽  
Low Concentrations ◽  
Substance P Receptor ◽  
Maximal Binding ◽  
Fold Excess

Interactions between neutral endopeptidase-24.11 (NEP) and the substance P receptor (SPR; NK1) were investigated by examining substance P (SP) degradation, SP binding and SP-induced Ca2+ mobilization in epithelial cells transfected with cDNA encoding the rat SPR and rat NEP. Expression of NEP accelerated the degradation of SP by intact epithelial cells and by membrane preparations, and degradation was reduced by the NEP inhibitor thiorphan. In cells expressing SPR alone, specific 125I-SP binding after 20 min incubation at 37 degrees C was 92.2 +/- 3.1% of maximal binding and was unaffected by thiorphan. Coexpression of NEP in the same cells as the SPR markedly reduced SP binding to 13.9 +/- 0.5% of maximal, and binding was increased to 82.7 +/- 2.4% of maximal with thiorphan. Coexpression of NEP in the same cells as the SPR also reduced to undetectable the increase in intracellular Ca2+ in response to low concentrations of SP (0.3 and 0.5 nM), and significantly reduced the response to higher concentrations (1 and 3 nM). The Ca2+ response was restored to control values by inhibition of NEP with thiorphan. In contrast, SP binding and SP-induced Ca2+ mobilization were only slightly reduced when cells expressing SPR alone were mixed with a 3- to 24-fold excess of cells expressing NEP alone. Therefore, in this system, NEP markedly down-regulates SP binding and SP-induced Ca2+ mobilization only when coexpressed in the same cells as the SPR.

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