Electrogenic Sodium Pump in Squid Giant Axon

Science ◽  
1973 ◽  
Vol 179 (4080) ◽  
pp. 1326-1328 ◽  
Author(s):  
P. De Weer ◽  
D. Geduldig
Keyword(s):  
Sodium Pump ◽  
Giant Axon ◽  
Squid Giant Axon ◽  
Electrogenic Sodium Pump

scholarly journals Strophanthidin-sensitive sodium fluxes in metabolically poisoned frog skeletal muscle.

1976 ◽  
Vol 68 (4) ◽  
pp. 405-420 ◽  
Author(s):  
B G Kennedy ◽  
P De Weer
Keyword(s):  
Skeletal Muscle ◽  
Membrane Potential ◽  
Human Erythrocyte ◽  
Sodium Pump ◽  
Giant Axon ◽  
Squid Giant Axon ◽  
Frog Skeletal Muscle ◽  
Na Efflux ◽  
Unidirectional Fluxes ◽  
External K

Strophanthidin-sensitive and insensitive unidirectional fluxes of Na were measured in fog sartorius muscles whose internal Na levels were elevated by overnight storage in the cold. ATP levels were lowered, and ADP levels raised, by metabolic poisoning with either 2,4-dinitrofluorobenzene or iodoacetamide. Strophanthidin-sensitive Na efflux and influx both increased after poisoning, while strophanthidin-insensitives fluxes did not. The increase in efflux did not require the presence of external K but was greatly attenuated when Li replaced Na as the major external cation. Membrane potential was not markedly altered by 2,4-dinitrofluorobenzene. These observations indicate that the sodium pump of frog skeletal muscle resembles that of squid giant axon and human erythrocyte in its ability to catalyze Na-Na exchange to an extent determined by intracellular ATP/ADP levels.

Effects of pH changes on sodium pump fluxes in squid giant axon

1987 ◽  
Vol 253 (4) ◽  
pp. C547-C554 ◽  
Author(s):  
G. E. Breitwieser ◽  
A. A. Altamirano ◽  
J. M. Russell
Keyword(s):  
Sodium Pump ◽  
Maximum Velocity ◽  
Activation Parameters ◽  
Giant Axon ◽  
Inhibitory Effect ◽  
Squid Giant Axon ◽  
Extracellular Ph ◽  
Sodium Efflux ◽  
Effects Of Ph ◽  
Ph Range

The effects of independently varying intracellular and extracellular pH on sodium pump fluxes were studied in the squid giant axon. By means of intracellular dialysis, we found that changes of intracellular pH (pHi), but not of extracellular pH, affected ouabain-sensitive Na+ efflux and K+ influx over the pH range of 6.0-8.6. Both fluxes were maximum at a pHi of 7.2-7.4. Variations away from this optimal pHi in either the acidic or alkaline direction resulted in a graded inhibition of both ouabain-sensitive fluxes. The kinetic basis for the inhibitory effect of acidic pHi was examined by comparing the kinetic parameters of activation of ouabain-sensitive sodium efflux by intracellular Na+ (Na+i) and extracellular K+ (K+o) at normal pHi with those at acidic pHi. We found that the inhibitory effect of intracellular acidity results from a reversible decrease in maximum velocity (Vmax), without an effect on the activation parameters for Na+i (K1/2 Na+i) or K+o (K1/2 K+o).

Effects of Intracellular ADP and Pi on the Sodium Pump of Squid Giant Axon

Nature ◽  
1970 ◽  
Vol 226 (5252) ◽  
pp. 1251-1252 ◽  
Author(s):  
P. DE WEER
Keyword(s):  
Sodium Pump ◽  
Giant Axon ◽  
Squid Giant Axon

Neurofilaments and Paired Helical Filaments

1985 ◽  
Vol 43 ◽  
pp. 740-743
Author(s):  
J. Metuzals
Keyword(s):  
Animal Model ◽  
Posttranslational Modifications ◽  
Posttranslational Modification ◽  
Giant Axon ◽  
Paired Helical Filaments ◽  
Squid Giant Axon ◽  
In Vitro Experiments ◽  
Thin Sections ◽  
Structural Relationships

It has been demonstrated that the neurofibrillary tangles in biopsies of Alzheimer patients, composed of typical paired helical filaments (PHF), consist also of typical neurofilaments (NF) and 15nm wide filaments. Close structural relationships, and even continuity between NF and PHF, have been observed. In this paper, such relationships are investigated from the standpoint that the PHF are formed through posttranslational modifications of NF. To investigate the validity of the posttranslational modification hypothesis of PHF formation, we have identified in thin sections from frontal lobe biopsies of Alzheimer patients all existing conformations of NF and PHF and ordered these conformations in a hypothetical sequence. However, only experiments with animal model preparations will prove or disprove the validity of the interpretations of static structural observations made on patients. For this purpose, the results of in vitro experiments with the squid giant axon preparations are compared with those obtained from human patients. This approach is essential in discovering etiological factors of Alzheimer's disease and its early diagnosis.

Injury-induced vesiculation and membrane redistribution in squid giant axon

1990 ◽  
Vol 1023 (3) ◽  
pp. 421-435 ◽  
Author(s):  
Harvey M. Fishman ◽  
Kirti P. Tewari ◽  
Philip G. Stein
Keyword(s):  
Giant Axon ◽  
Squid Giant Axon

Anterograde Transport of Peptide-Conjugated Fluorescent Beads in the Squid Giant Axon Identifies a Zip-Code for the Synapse

2004 ◽  
Vol 207 (2) ◽  
pp. 164-164
Author(s):  
Michael P. Conley ◽  
Marcus K. Jang ◽  
Joseph A. DeGiorgis ◽  
Elaine L. Bearer
Keyword(s):  
Giant Axon ◽  
Squid Giant Axon ◽  
Anterograde Transport ◽  
Fluorescent Beads ◽  
Zip Code

scholarly journals Determination of Transmembrane Protein with Diazotized (125I)-Iodosulfanilic Acid in the Squid Giant Axon

1978 ◽  
Vol 54 (6) ◽  
pp. 310-315 ◽  
Author(s):  
Tohru YOSHIOKA ◽  
Toshifumi TAKENAKA ◽  
Hidenori HORIE ◽  
Hiroko INOUE ◽  
Kimie INOMATA
Keyword(s):  
Transmembrane Protein ◽  
Giant Axon ◽  
Squid Giant Axon

On the mechanism of the electrogenic sodium pump dependence of membrane chemosensitivity

1979 ◽  
Vol 64 (4) ◽  
pp. 601-604 ◽  
Author(s):  
S.N Ayrapetyan ◽  
V.L Arvanov
Keyword(s):  
Sodium Pump ◽  
Electrogenic Sodium Pump
Sign in / Sign up

Export Citation Format

Share Document