Relation between Extracellular Potassium Ion Concentration and Contracture Force after Abolition of Spike Discharge in Isolated Rat Portal Vein

1974 ◽  
Vol 11 (3) ◽  
pp. 120-127
Author(s):  
Bengt Uvelius ◽  
Börje Johansson
Keyword(s):  
Portal Vein ◽  
Potassium Ion ◽  
Ion Concentration ◽  
Extracellular Potassium ◽  
Spike Discharge ◽  
Rat Portal Vein ◽  
Isolated Rat

scholarly journals In Vivo Neocortical [K]o Modulation by Targeted Stimulation of Astrocytes

2021 ◽  
Vol 22 (16) ◽  
pp. 8658
Author(s):  
Azin EbrahimAmini ◽  
Shanthini Mylvaganam ◽  
Paolo Bazzigaluppi ◽  
Mohamad Khazaei ◽  
Alexander Velumian ◽  
...  
Keyword(s):  
Nervous System ◽  
Membrane Potential ◽  
Potassium Ion ◽  
Ion Concentration ◽  
Extracellular Potassium ◽  
Spreading Depolarization ◽  
Potential Tool ◽  
Stimulation Of

A normally functioning nervous system requires normal extracellular potassium ion concentration ([K]o). Throughout the nervous system, several processes, including those of an astrocytic nature, are involved in [K]o regulation. In this study we investigated the effect of astrocytic photostimulation on [K]o. We hypothesized that in vivo photostimulation of eNpHR-expressing astrocytes leads to a decreased [K]o. Using optogenetic and electrophysiological techniques we showed that stimulation of eNpHR-expressing astrocytes resulted in a significantly decreased resting [K]o and evoked K responses. The amplitude of the concomitant spreading depolarization-like events also decreased. Our results imply that astrocytic membrane potential modification could be a potential tool for adjusting the [K]o.

THE INFLUENCE OF POTASSIUM ION UPON GLUCOSE UPTAKE AND GLYCOGEN SYNTHESIS IN THE ISOLATED RAT DIAPHRAGM

1955 ◽  
Vol 33 (1) ◽  
pp. 687-694 ◽  
Author(s):  
D. W. Clarke
Keyword(s):  
Glucose Uptake ◽  
Glycogen Synthesis ◽  
Potassium Ion ◽  
Ion Concentration ◽  
Rat Diaphragm ◽  
High Potassium ◽  
High Concentrations ◽  
Glycogen Breakdown ◽  
Isolated Rat

The amounts of glucose taken from a medium, and the amounts of glycogen synthesized, by rat hemidiaphragms were studied under various conditions. High concentrations of potassium ion inhibited the glucose uptake and there was also a reduced net glycogen synthesis. Glycogen breakdown was probably not increased by high potassium ion concentration. The effect of potassium was most marked when conditions were such that one would ordinarily expect a considerable glucose uptake or glycogen synthesis. The action of insulin was not peculiarly susceptible to potassium ion inhibition.

Quantitative Characterization of Epicardial Wave Fronts During Regional Ischemia and Elevated Extracellular Potassium Ion Concentration

10.1114/1.136 ◽  
1998 ◽  
Vol 26 (6) ◽  
pp. 1010-1021 ◽  
Author(s):  
Bonnie B. Punske ◽  
Wayne E. Cascio ◽  
Connie Engle ◽  
H. Troy Nagle ◽  
Leonard S. Gettes ◽  
...  
Keyword(s):  
Potassium Ion ◽  
Ion Concentration ◽  
Extracellular Potassium ◽  
Wave Fronts ◽  
Quantitative Characterization ◽  
Regional Ischemia

Possible interactions between neurotensin and prostaglandins in the isolated rat portal vein

Life Sciences ◽  
1980 ◽  
Vol 27 (3) ◽  
pp. 259-267 ◽  
Author(s):  
F. Rioux ◽  
R. Quirion ◽  
M.A. Leblanc ◽  
D. Regoli ◽  
S. St-Pierre
Keyword(s):  
Portal Vein ◽  
Rat Portal Vein ◽  
Isolated Rat

scholarly journals High extracellular potassium ion concentration attenuates the blockade action of ketanserin on Kv1.3 channels expressed in xenopus oocytes

2008 ◽  
Vol 121 (24) ◽  
pp. 2584-2591
Author(s):  
Zhen-tao LIANG ◽  
Xian-pei WANG ◽  
Qiu-tang ZENG ◽  
Yu-hua LIAO ◽  
An-ruo ZOU ◽  
...  
Keyword(s):  
Xenopus Oocytes ◽  
Potassium Ion ◽  
Ion Concentration ◽  
Extracellular Potassium ◽  
Kv1.3 Channels

Modifications evoked by piretanide in the mechanical activity of cardiovascular tissues

1985 ◽  
Vol 63 (4) ◽  
pp. 283-286
Author(s):  
J. L. Lacuara ◽  
R. D. Ruiz ◽  
M. Fiol de Cuneo
Keyword(s):  
Portal Vein ◽  
Contractile Activity ◽  
Mechanisms Of Action ◽  
Mechanical Activity ◽  
Vascular Tissues ◽  
Cardiovascular Tissues ◽  
Rat Portal Vein ◽  
Isolated Rat

The effects of piretanide upon mechanical activity and pharmacological reactivity of vascular and myocardial tissues from normotensive rats were investigated. Magnitude of phasic contractions of isolated rat portal vein was diminished by the drug in a dose-related manner; contractile depression induced by piretanide (10−4 M) was less in the presence of insulin (0.1 U/mL), glucose (22 mM) or pyruvate (5 mM). Responses to KCl (90 mM), or norepinephrine (2.5 × 10−5 M) were also reduced. Contractile activity of atria and ventricle strips was diminished only when piretanide reached 10−4 M. Results support direct actions of piretanide upon cardiac and vascular tissues. Possible mechanisms of action are discussed.

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