Chloride ion efflux during an action potential in the main pulvinus ofMimosa pudica

1981 ◽  
Vol 94 (4) ◽  
pp. 379-383 ◽  
Author(s):  
Takeshi Abe
Keyword(s):  
Action Potential ◽  
Chloride Ion ◽  
Ion Efflux ◽  
Main Pulvinus

scholarly journals The Electrical Measurement of Chloride Fluxes in Nitella

1966 ◽  
Vol 19 (3) ◽  
pp. 385 ◽  
Author(s):  
DS Mailman ◽  
I JMullins
Keyword(s):  
Thin Film ◽  
Action Potential ◽  
Effective Diffusion ◽  
Diffusion Constant ◽  
Chloride Ion ◽  
Electrical Measurement ◽  
Chloride Diffusion ◽  
Diffusion Resistance ◽  
Free Solution ◽  
Cell Changes

The chloride efflux from cells of Nitella olavata at rest and during an action potential was continuously monitored by a Ag/AgGl electrode which measured the concentration of chloride in a thin film of solution flowing over the surface of the cell. Changes in the concentration of chloride subsequent to the passage of an action potential were followed and permitted calculation of the change in the flux of chloride ion across the cell membrane. The cell wall offers appreciable diffusion resistance to chloride ion, the effective diffusion constant being less than 1 % of chloride diffusion in free solution. Resting fluxes of chloride were measured in these cells and averaged 3 pmole/cm2 sec. The extra efflux of chloride during an action potential averaged 114 pmole/cm2 impulse.

Action potential and rapid movement in the main pulvinus ofMimosa pudica

1972 ◽  
Vol 85 (2) ◽  
pp. 135-145 ◽  
Author(s):  
Kenji Oda ◽  
Takeshi Abe
Keyword(s):  
Action Potential ◽  
Rapid Movement ◽  
Main Pulvinus

scholarly journals Chloride ion efflux regulates adherence, spreading, and respiratory burst of neutrophils stimulated by tumor necrosis factor-alpha (TNF) on biologic surfaces.

1996 ◽  
Vol 135 (2) ◽  
pp. 511-522 ◽  
Author(s):  
R Menegazzi ◽  
S Busetto ◽  
P Dri ◽  
R Cramer ◽  
P Patriarca
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis Factor Alpha ◽  
Respiratory Burst ◽  
Tumor Necrosis ◽  
Chloride Ion ◽  
Early Event ◽  
Necrosis Factor Alpha ◽  
Ion Efflux ◽  
Factor Alpha ◽  
Necrosis Factor

Chloride ion efflux is an early event occurring after exposure of neutrophilic polymorphonuclear leukocytes (PMN) in suspension to several agonists, including cytokines such as tumor necrosis factor-alpha (TNF) and granulocyte/macrophage-colony stimulating factor (Shimizu, Y., R.H. Daniels, M.A. Elmore, M.J. Finnen, M.E. Hill, and J.M. Lackie. 1993. Biochem. Pharmacol. 9:1743-1751). We have studied TNF-induced Cl- movements in PMN residing on fibronectin (FN) (FN-PMN) and their relationships to adherence, spreading, and activation of the respiratory burst. Occupancy of the TNF-R55 and engagement of beta 2 integrins cosignaled for an early, marked, and prolonged Cl- efflux that was accompanied by a fall in intracellular chloride levels (Cl-i). A possible causal relationship between Cl- efflux, adherence, and respiratory burst was first suggested by kinetic studies, showing that TNF-induced Cl- efflux preceded both the adhesive and metabolic response, and was then confirmed by inhibition of all three responses by pretreating PMN with inhibitors of Cl- efflux, such as ethacrynic acid. Moreover, Cl- efflux induced by means other than TNF treatment, i.e., by using Cl(-)-free media, was followed by increased adherence, spreading, and metabolic activation, thus mimicking TNF effects. These studies provide the first evidence that a drastic decrease of Cl-i in FN-PMN may represent an essential step in the cascade of events leading to activation of proadhesive molecules, reorganization of the cytoskeleton network, and assembly of the O2(-)-forming NADPH oxidase.

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