scholarly journals The Roles of Sodium and Potassium Ions in the Generation of the Electro-Olfactogram

1968 ◽  
Vol 51 (4) ◽  
pp. 552-578 ◽  
Author(s):  
Sadayuki F. Takagi ◽  
Gordon A. Wyse ◽  
Harunobu Kitamura ◽  
Katsuhiro Ito
Keyword(s):  
Essential Role ◽  
Ringer Solution ◽  
The Other ◽  
Potassium Ions ◽  
Ionic Mechanism ◽  
Ringer’S Solution ◽  
Sodium And Potassium

In order to clarify whether or not the electronegative olfactory mucosal potentials (EOG) are generator potentials, the effects of changed ionic enviroment were studied. The EOG decreased in amplitude and in some cases nearly or completely disappeared, when Na+ in the bathing Ringer solution was replaced by sucrose, Li+, choline+, tetraethylammonium+ (TEA), or hydrazine. In the K+-free Ringer solution, the negative EOG's initially increased and then decreased in amplitude. In Ringer's solution with increased K+, the negative EOG's increased in amplitude. When K+ was increased in exchange for Na+ in Ringer's solution, the negative EOG's decreased, disappeared, and then reversed their polarity (Fig. 6). Next, when the K+ was replaced by equimolar sucrose, Li+, choline+, TEA+, hydrazine, or Na+, the reversed potentials recovered completely only in Na+-Ringer's solution, but never in the other solutions. Thus, the essential role of Na+ and K+ in the negative EOG's was demonstrated. Ba++ was found to depress selectively the electropositive EOG, but it hardly decreased and never increased the negative EOG. Hence, it is concluded that Ba++ interferes only with Cl- influx, and that the negative EOG's are elicited by an increase in permeability of the olfactory receptive membrane to Na+ and K+, but not to Cl-. From the ionic mechanism it is inferred that the negative EOG's are in most cases composites of generator and positive potentials.

The Gastronomy of the Eye

2020 ◽  
pp. 175-198
Author(s):  
Vrushali Dhage
Keyword(s):  
Essential Role ◽  
Historical Perspective ◽  
Smart Cities ◽  
Methodological Approach ◽  
Economic Liberalization ◽  
The Other ◽  
Works Of Art

Works of art can be read at various levels: from being objects of simple retinal pleasure to the other extreme of being significant critical statements of their time. This chapter aims to strike a cerebral dialogue through the works of art. The current study shall consider the latter function of art and analyze the methods in which contemporary Indian artists have made attempts to provide a critique of the early initiatives towards developing Delhi and Mumbai as ‘smart cities'. The review of works from India concludes the essential role of infrastructural projects and envisioned spaces built in the era of economic liberalization. The study aims at drawing a methodological approach, with an art historical perspective, with the artists analysing and translating the urban experiential phenomenon, into artworks.

Separation of sodium and potassium ion carrier systems in crustacean motor axon

1962 ◽  
Vol 202 (5) ◽  
pp. 856-864 ◽  
Author(s):  
Ernest B. Wright ◽  
Tadao Tomita
Keyword(s):  
Membrane Resistance ◽  
The Other ◽  
Motor Axon ◽  
Potassium Ions ◽  
High Potassium ◽  
Rich Media ◽  
Inward Currents ◽  
Ion Carrier ◽  
Carrier Systems ◽  
Sodium And Potassium

When a microscopic area (100 µ length) of the lobster single motor axon is subjected to isotonic potassium solution and the membrane potential maintained at resting level by an applied voltage, a slow prolonged depolarization may be elicited by adequate cathodal stimuli. This response is due to activity of the potassium carrier system. If some sodium chloride is included in the high potassium solution, both spike and prolonged depolarization may be initiated as a spike-dip-plateau. With normal amount of sodium in excess potassium solution the dip is absent, but the membrane resistance shows a remarkable increase at the juncture of the spike and the plateau. Chronaxie values of the spike are 0.4–0.5 msec, of the slow response 2.1–2.2 msec. In potassium-rich media containing sodium two separate inward currents are recorded during a voltage clamp, an early spikelike current, and a late prolonged one. It is concluded that two separate ion carrier systems are activated in a nerve membrane during excitation, one specific to sodium ions, the other to potassium ions, each system possessing quite different and independent characteristics from the other.

scholarly journals RNA polymerase II plays an active role in the formation of gene loops through the Rpb4 subunit

2019 ◽  
Vol 47 (17) ◽  
pp. 8975-8987 ◽  
Author(s):  
Paula Allepuz-Fuster ◽  
Michael J O’Brien ◽  
Noelia González-Polo ◽  
Bianca Pereira ◽  
Zuzer Dhoondia ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Essential Role ◽  
Transcription Termination ◽  
Active Role ◽  
The Other ◽  
Loop Formation ◽  
Direct Role

AbstractGene loops are formed by the interaction of initiation and termination factors occupying the distal ends of a gene during transcription. RNAPII is believed to affect gene looping indirectly owing to its essential role in transcription. The results presented here, however, demonstrate a direct role of RNAPII in gene looping through the Rpb4 subunit. 3C analysis revealed that gene looping is abolished in the rpb4Δ mutant. In contrast to the other looping-defective mutants, rpb4Δ cells do not exhibit a transcription termination defect. RPB4 overexpression, however, rescued the transcription termination and gene looping defect of sua7-1, a mutant of TFIIB. Furthermore, RPB4 overexpression rescued the ssu72-2 gene looping defect, while SSU72 overexpression restored the formation of gene loops in rpb4Δ cells. Interestingly, the interaction of TFIIB with Ssu72 is compromised in rpb4Δ cells. These results suggest that the TFIIB–Ssu72 interaction, which is critical for gene loop formation, is facilitated by Rpb4. We propose that Rpb4 is promoting the transfer of RNAPII from the terminator to the promoter for reinitiation of transcription through TFIIB–Ssu72 mediated gene looping.

scholarly journals Role of sodium and potassium ions in regulation of glucose metabolism in cultured astroglia.

1995 ◽  
Vol 92 (10) ◽  
pp. 4616-4620 ◽  
Author(s):  
S. Takahashi ◽  
B. F. Driscoll ◽  
M. J. Law ◽  
L. Sokoloff
Keyword(s):  
Glucose Metabolism ◽  
Potassium Ions ◽  
Sodium And Potassium

scholarly journals Temperature-dependence of activation and inhibition of rat-brain adenosine triphosphatase activated by sodium and potassium ions

1966 ◽  
Vol 100 (3) ◽  
pp. 762-767 ◽  
Author(s):  
N Gruener ◽  
Y Avi-Dor
Keyword(s):  
Rat Brain ◽  
Adenosine Triphosphatase ◽  
Arrhenius Plot ◽  
Enzyme System ◽  
The Other ◽  
Potassium Ions ◽  
Adenosine Triphosphatase Activity ◽  
Brain Microsomes ◽  
High Concentrations ◽  
Sodium And Potassium

1. The adenosine-triphosphatase activity of rat-brain microsomes was measured between 0 degrees and 37 degrees . The stimulatory effect of Na(+) plus K(+) on the Mg(2+)-dependent adenosine-triphosphatase activity decreased sharply with decreasing temperature and became negligible at 0 degrees . An Arrhenius plot drawn from the experimental data showed two discontinuities: one at about 6 degrees and the other at about 20 degrees . 2. The increment in activity induced by Na(+) plus K(+) was more sensitive to oligomycin at lower than at higher temperatures, but the opposite was observed for ouabain. The action of oligomycin showed a biphasic character, since below a certain concentration it caused slight activation of Na(+)-plus-K(+)-activated adenosine triphosphatase. 3. Where oligomycin increased the activity of the enzyme, it also enhanced the accumulation of an acid-precipitable phosphorylated compound formed through the transfer of the gamma-phosphate group of [(32)P]ATP to the enzyme system. Stimulatory concentrations of oligomycin did not interfere with K(+)-mediated dephosphorylation of the intermediate, though high concentrations of oligomycin counteracted the effect of K(+). 4. The temperature profile of K(+)-stimulated microsomal phosphatase qualitatively resembled that of microsomal adenosine triphosphatase.

scholarly journals Basal Glutathionylation of Na,K-ATPaseα-Subunit Depends on Redox Status of Cells during the Enzyme Biosynthesis

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Vladimir A. Mitkevich ◽  
Irina Yu. Petrushanko ◽  
Yuri M. Poluektov ◽  
Ksenia M. Burnysheva ◽  
Valentina A. Lakunina ◽  
...  
Keyword(s):  
Acute Hypoxia ◽  
Viral Proteins ◽  
Redox Status ◽  
Cysteine Residues ◽  
Potassium Ions ◽  
X Ray ◽  
Pig Kidney ◽  
Sodium And Potassium ◽  
Enzyme Biosynthesis

Many viruses induce oxidative stress and cause S-glutathionylation of Cys residues of the host and viral proteins. Changes in cell functioning during viral infection may be associated with glutathionylation of a number of key proteins including Na,K-ATPase which creates a gradient of sodium and potassium ions. It was found that Na,K-ATPaseα-subunit has a basal glutathionylation which is not abrogated by reducing agent. We have shown that acute hypoxia leads to increase of total glutathionylation level of Na,K-ATPaseα-subunit; however, basal glutathionylation ofα-subunit increases under prolonged hypoxia only. The role of basal glutathionylation in Na,K-ATPase function remains unclear. Understanding significance of basal glutathionylation is complicated by the fact that there are no X-ray structures of Na,K-ATPase with the identified glutathione molecules. We have analyzed all X-ray structures of the Na,K-ATPaseα-subunit from pig kidney and found that there are a number of isolated cavities with unresolved electron density close to the relevant cysteine residues. Analysis of the structures showed that this unresolved density in the structure can be occupied by glutathione associated with cysteine residues. Here, we discuss the role of basal glutathionylation of Na,K-ATPaseα-subunit and provide evidence supporting the view that this modification is cotranslational.

scholarly journals DRIS Norms and Sufficiency Ranges for Pepper Grown under Greenhouses Conditions in the Southeast of Spain

Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 837
Author(s):  
Alfonso Llanderal ◽  
Pedro García-Caparrós ◽  
María Teresa Lao ◽  
Maria Luz Segura
Keyword(s):  
Capsicum Annuum ◽  
Fruit Development ◽  
Essential Role ◽  
Integrated System ◽  
The Other ◽  
Phenological Stages ◽  
Capsicum Annuum L ◽  
Crop Nutrition

The aim of this study was to compile DRIS (Diagnosis and Recommendation Integrated System) norms and sufficiency ranges for pepper grown in greenhouses and the determination of the variation in DRIS norms and sufficiency ranges during the different phenological stages of the crop. The DRIS norms and sufficiency ranges were constituted by 367 leaf samples of Capsicum annuum L. which were collected in different phenological stages of the crop (flowering (FL), fruiting (FT), fruit development (FD), and harvesting (HV)). Two sufficiency ranges were developed; one including all leaf samples and the other considering the leaf samples by phenological stages ((FL) (44), (FT) (96), (FD) (100), and (HV) (127)). Furthermore, 10 DRIS norms and CV were calculated from N, P, K, Ca, and Mg. Two ratios of them were calculated in FL (N/P and N/K), two in FD (N/P and Ca/N) and one in HV (N/P) showing low CV, meaning, according to DRIS norms, the essential role of these nutrients in the crop nutrition. Moreover, the sufficiency ranges computed by all database were: N (34–56), P (1.9–4.3), K (30–51), Ca (12–33), and Mg (4.0–15) (mg g−1 DW), respectively. The data obtained in this experiment highlighted the importance of the sensitivity (low CV) of nutrient in the phenological stages such as happened with N.

Sign in / Sign up

Export Citation Format

Share Document