Plateau Formation and Sulphydryl Groups in the Plasma Membrane

Takahashi, Hidehiko; Murai, Takayoshi; Sasaki, Toshi

doi:10.1038/1821675a0

Cited by 20 publications

(6 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The possiblity that the photodynamic effect on cellular excitation works via membrane proteins receives independent support from experiments where other agents which alter proteins also alter electrical properties. Examples of this are internal perfusion with Pronase (Calbiochem, Los Angeles, Calif.) (Rojas and Armstrong, 1972), protein cross-link formation with aldehydes (Shrager et al, 1969), treatment with sulfhydryl reagents (Takahashi et al, 1958), and treatment with oxidizing agents (Huneeus-Cox et al, 1966). Prolongation of action potentials or sodium currents is a common feature of these treatments which alter membrane proteins and is a characteristic feature of photodynamic alteration.…”

Section: Discussionmentioning

confidence: 99%

Photodynamic Alteration of Sodium Currents in Lobster Axons

Pooler

1972

The Journal of General Physiology

View full text Add to dashboard Cite

Photodynamic alteration of lobster giant axons drastically changed the magnitude and kinetics of sodium currents seen under voltage clamp using the sucrose gap technique. Illumination of axons following treatment with acridine orange or eosin Y decreased the maximum sodium conductance to a zero asymptote as an exponential function of illumination time. Normal sodium inactivation was slowed, with rh more than doubled depending on experimental conditions. A second slower inactivation rate developed occasionally. rm was altered little, if at all. Sodium current "tails" were not prolonged. At maximum light intensity and with eosin Y as sensitizer leakage current increased after 4-10 sec in light. These changes were irreversible. Decreases in maximum sodium conductance correlated highly with increases in time to peak sodium current. The magnitude of change varied linearly with light intensity. The action spectra for eosin Y and acridine orange peaked near 545 and 505 nm, respectively. The magnitude of change varied with preillumination dye exposure time in a quasi-exponential approach to a maximum effect. Sodium dithionite protected the axon from photodynamic change.

show abstract

Section: Discussionmentioning

confidence: 99%

Photodynamic Alteration of Sodium Currents in Lobster Axons

Pooler

1972

The Journal of General Physiology

View full text Add to dashboard Cite

show abstract

“…We assumed at first that the excellency of some metals in the plateau formation was due to -S-Me-S-(Me represents divalent metals) linkage (Takahashi et al, 1958).…”

Section: Discussionmentioning

confidence: 99%

Some Chemical Aspect of Plateau Formation in the Action Current of the Myelinated Nerve Fibre

1960

Self Cite

View full text Add to dashboard Cite

“…It is known that for example Hg2+ breaks disulphide bridges in many proteins and forms sulphide groups, thus destroying the tertiary shape. It has been proposed that this is the mechanism by which Hg2+ affects the shape of the action potential in cardiac muscle (Takahashi et al 1958).…”

Section: Heavy Metals On Nerve2mentioning

confidence: 99%

Effects of some heavy metal ions on the ionic currents of myelinated fibres from Xenopus laevis.

Århem¹

1980

The Journal of Physiology

View full text Add to dashboard Cite

1. The effect of the heavy metal ions Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+ and Hg2+ on permeability parameters of the nerve membrane was investigated. The ions were applied externally to single myelinated fibres of Xenopus laevis. The ionic currents, associated with potential steps were measured and analysed. 2. Zn2+ reversibly slowed down the kinetics of the K system. The effect at large potential steps was described as an increase of tau n. 3.4 mM-Zn2+ increased tau n about three times. 3. Ni2+ and Cu2+ also reversibly increased tau n in a similar way. The effect was larger than that of Zn2+. The other period 4 ions tested did not affect tau n markedly. Nor did the group 2b ion Cd2+. 4. The relative efficiency of the different ions agreed well with their tendency to form complexes with certain ligands. The effect was not a simple function of affinity for sulphydryl groups. 5. All the studied ions decreased PNa. The decrease was reversible except for that caused by Hg2+. Cu2+ caused the largest reversible effect. Hg2+ irreversibly decreased PNa at low concentrations (1-10 microM). 6. All ions studied shifted the Na activation curve in a positive direction along the potential axis. The effect was reversible except for that caused by Hg2+. The largest reversible shift was caused by Cu2+. 7. The relative efficiency of the different ions on the parameters studied in Xenopus axons showed great similarity to the corresponding efficiency on axons from other species, although some differences were noted.

show abstract

Plateau Formation and Sulphydryl Groups in the Plasma Membrane

Cited by 20 publications

References 4 publications

Photodynamic Alteration of Sodium Currents in Lobster Axons

Photodynamic Alteration of Sodium Currents in Lobster Axons

Some Chemical Aspect of Plateau Formation in the Action Current of the Myelinated Nerve Fibre

Effects of some heavy metal ions on the ionic currents of myelinated fibres from Xenopus laevis.

Contact Info

Product

Resources

About