Effect of novocain on electrical activity of a single node of ranvier in solutions with high and low sodium ion concentrations

1967 ◽  
Vol 64 (4) ◽  
pp. 1078-1081
Author(s):  
V. I. Belyaev
Keyword(s):  
Electrical Activity ◽  
Node Of Ranvier ◽  
Sodium Ion ◽  
Single Node ◽  
Ion Concentrations ◽  
Low Sodium

Effects of sodium ion and solution tonicity on reactivities of hypertensive rat aortic strips

1960 ◽  
Vol 198 (5) ◽  
pp. 1019-1022 ◽  
Author(s):  
Samuel Mallov
Keyword(s):  
Drinking Water ◽  
Sodium Ion ◽  
Ion Concentration ◽  
Nacl Solution ◽  
Hypertensive Rats ◽  
Initial Tension ◽  
Low Concentration ◽  
Ion Concentrations ◽  
Low Sodium ◽  
Hypertensive Rat

Rats were rendered hypertensive by injecting DCA and feeding 1% NaCl solution in place of drinking water. Isometric tensions developed by strips of aorta from these rats, when exposed to a low concentration of epinephrine, were compared with tensions developed by strips from normotensive controls, under conditions of varying Na ion concentration and solution tonicity. Solutions with high Na ion concentrations (hypertonic), and normal solutions rendered equivalently hypertonic by the addition of sucrose, increased the reactivities of strips from normotensive rats, but decreased the reactivities of strips from hypertensive rats, to added epinephrine. The hypertensive rat strips manifested increases in tension in these solutions even prior to the addition of epinephrine, so that the subsequent smaller responses to epinephrine may have been related to these initial tension increases. Low sodium ion concentrations in hypotonic solutions, but not in isotonic solutions, decreased the reactivities of both hypertensive and normotensive rat strips. These results are interpreted to mean that aortas from hypertensive rats are so changed structurally and functionally, that they respond differently than do normal aortas to increased sodium ion concentrations and/or hypertonic solutions, as well as to epinephrine in such solutions.

scholarly journals Identification of a Meningococcal l-Glutamate ABC Transporter Operon Essential for Growth in Low-Sodium Environments

2006 ◽  
Vol 74 (3) ◽  
pp. 1725-1740 ◽  
Author(s):  
Caterina Monaco ◽  
Adelfia Talà ◽  
Maria Rita Spinosa ◽  
Cinzia Progida ◽  
Eleanna De Nitto ◽  
...  
Keyword(s):  
Abc Transporter ◽  
Cell Invasion ◽  
Mutant Cell ◽  
Defined Medium ◽  
Sodium Ion ◽  
Ion Concentration ◽  
Low Sodium ◽  
Defective Mutant ◽  
Secondary Transporter ◽  
Genes Encoding

ABSTRACT GdhR is a meningococcal transcriptional regulator that was previously shown to positively control the expression of gdhA, encoding the NADP-specific l-glutamate dehydrogenase (NADP-GDH), in response to the growth phase and/or to the carbon source. In this study we used reverse transcriptase-PCR-differential display (to identify additional GdhR-regulated genes. The results indicated that GdhR, in addition to NADP-GDH, controls the expression of a number of genes involved in glucose catabolism by the Entner-Doudoroff pathway and in l-glutamate import by an unknown ABC transport system. The genes encoding the putative periplasmic substrate-binding protein (NMB1963) and the permease (NMB1965) of the ABC transporter were genetically inactivated. Uptake experiments demonstrated an impairment of l-glutamate import in the NMB1965-defective mutant in the absence or in the presence of a low sodium ion concentration. In contrast, at a sodium ion concentration above 60 mM, the uptake defect disappeared, possibly because the activity of a sodium-driven secondary transporter became predominant. Indeed, the NMB1965-defective mutant was unable to grow at a low sodium ion concentration (<20 mM) in a chemically defined medium containing l-glutamate and four other amino acids that supported meningococcal growth, but it grew when the sodium ion concentration was raised to higher values (>60 mM). The same growth phenotype was observed in the NMB1963-defective mutant. Cell invasion and intracellular persistence assays and expression data during cell invasion provided evidence that the l-glutamate ABC transporter, tentatively named GltT, was critical for meningococcal adaptation in the low-sodium intracellular environment.

Sodium-Induced Changes in the Nuclei of Monolayer Hela Cultures

1972 ◽  
Vol 11 (3) ◽  
pp. 669-673
Author(s):  
K. JOBST ◽  
N. KELLERMAYER
Keyword(s):  
Culture Medium ◽  
Structural Rearrangement ◽  
Sodium Ion ◽  
Ion Concentration ◽  
Sodium Ions ◽  
Hypertonic Medium ◽  
Low Sodium ◽  
Large Numbers ◽  
Induced Changes ◽  
Cells Cultured

In HeLa cells cultured in a medium containing 142 mequiv./l. sodium ions only the mitotic forms are birefringent (anisotropic index, 27/1000). In a culture medium containing 155-160 mequiv./l. sodium ions, large numbers of nuclear forms reminiscent of the prophase were found. In such a medium the anisotropic index was 86/1000. At low sodium ion concentration (90-110 mequiv./l.) these anomalous, prophase-like forms were not seen and the anisotropic index was 18/1000. The appearance of the birefringent, prophase-like forms is related to a structural rearrangement and condensation of DNP in a hypertonic medium.

Rapid Induction of Hyperplasiain Vitroin Rat Bladder Explants by Elevated Sodium Ion Concentrations and Alkaline pH

1996 ◽  
Vol 138 (2) ◽  
pp. 219-230 ◽  
Author(s):  
Richard D. Storer ◽  
Lea R. Gordon ◽  
John Barnum ◽  
Keith Soper ◽  
Chennekatu P. Peter
Keyword(s):  
Sodium Ion ◽  
Alkaline Ph ◽  
Ion Concentrations ◽  
Rapid Induction ◽  
Rat Bladder

scholarly journals THE CHARACTERISTICS OF ULTRAFILTRATES OF PLASMA

1933 ◽  
Vol 16 (4) ◽  
pp. 637-655 ◽  
Author(s):  
Raymond C. Ingraham ◽  
Charles Lombard ◽  
Maurice B. Visscher
Keyword(s):  
Body Fluid ◽  
Chloride Ion ◽  
Chloride Anion ◽  
Sodium Ion ◽  
Hydrogen Ion ◽  
Substantial Agreement ◽  
Ion Concentrations ◽  
Alkaline Side ◽  
The Difference ◽  
Equilibrium Effect

1. Calculations from the Fick diffusion law are shown to predict that membrane equilibria should be established during the course of ultrafiltration. 2. It is shown that the chloride ion is more concentrated and the sodium ion less concentrated in the ultrafiltrate than in the plasma from which the ultrafiltrate was derived. 3. It has been found that by increasing the base bound by protein through a reduction in the bicarbonate content the difference between the plasma concentration and the ultrafiltrate concentration for the several ions studied increases. 4. Calculations from the Donnan equation as to the magnitude of the change in base bound by protein at differing hydrogen ion concentrations are in substantial agreement with the observed values, thus rendering it probable that the membrane equilibrium effect is responsible for the change in distribution ratios observed. 5. It is pointed out that the observed difference in the distribution ratio of cations from that of the chloride anion is probably to be explained by the influence of protein in lowering the activity coefficient of cations when on the alkaline side of the isoelectric point. 6. It is pointed out that account must be taken of these observations in any consideration of the rôle of ultrafiltration in the production of any secretion or body fluid.

Sodium ion binding in human serum.

1982 ◽  
Vol 28 (3) ◽  
pp. 449-452 ◽  
Author(s):  
T R Kissel ◽  
J R Sandifer ◽  
N Zumbulyadis
Keyword(s):  
Standard Addition ◽  
Sodium Ion ◽  
Ion Selective Electrode ◽  
Ion Selective Electrodes ◽  
Ion Binding ◽  
Selective Electrode ◽  
Titration Method ◽  
Low Sodium ◽  
Human Sera ◽  
Sodium Binding

Abstract The amount of sodium ion binding in human sera and in dialyzed human sera was estimated from standard-addition titrations with an ion-selective electrode and from measurements of 23Na nuclear magnetic resonance (NMR) linewidth. For the untreated sera, maximum binding was 1% (1.4 mmol/L) as indicated by NMR; virtually no binding was found via the titration method. For dialyzed sera with low-sodium, normal-protein content, NMR indicated that sodium binding was less than 1.3% (0.14 mmol/L). The same dialyzed fluid analyzed with ion-selective electrodes shows no sodium binding, within the limits of experimental error (+/- 4%). Sodium ion binding to serum protein thus contributes only minimally to differences in sodium measurements observed between the direct (undiluted) ion-selective electrode and flame-photometric methods.

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