scholarly journals Properties of toxin-resistant sodium channels produced by chemical modification in frog skeletal muscle.

1980 ◽  
Vol 305 (1) ◽  
pp. 485-500 ◽  
Author(s):  
B C Spalding
Keyword(s):  
Skeletal Muscle ◽  
Chemical Modification ◽  
Sodium Channels ◽  
Frog Skeletal Muscle

scholarly journals Modified kinetics and selectivity of sodium channels in frog skeletal muscle fibers treated with aconitine.

1982 ◽  
Vol 80 (5) ◽  
pp. 713-731 ◽  
Author(s):  
D T Campbell
Keyword(s):  
Skeletal Muscle ◽  
Sodium Channel ◽  
Sodium Channels ◽  
State Level ◽  
Steady State Level ◽  
Channel Block ◽  
Frog Skeletal Muscle ◽  
Channel Kinetics ◽  
Ionic Selectivity ◽  
Channel Selectivity

The effect of the plant alkaloid aconitine on sodium channel kinetics, ionic selectivity, and blockage by protons and tetrodotoxin (TTX) has been studied in frog skeletal muscle. Treatment with 0.25 or 0.3 mM aconitine alters sodium channels so that the threshold of activation is shifted 40-50 mV in the hyperpolarized direction. In contrast to previous results in frog nerve, inactivation is complete for depolarizations beyond about -60 mV. After aconitine treatment, the steady state level of inactivation is shifted approximately 20 mV in the hyperpolarizing direction. Concomitant with changes in channel kinetics, the relative permeability of the sodium channel to NH4,K, and Cs is increased. This altered selectivity is not accompanied by altered block by protons or TTX. The results suggest that sites other than those involved in channel block by protons and TTX are important in determining sodium channel selectivity.

The influence of temperature and frequency of stimulation on the impairment of excitability of frog skeletal muscle by local anesthetics and alkyl amphipathic agents

1985 ◽  
Vol 63 (10) ◽  
pp. 1327-1334 ◽  
Author(s):  
James G. Foulks ◽  
Lillian Morishita
Keyword(s):  
Skeletal Muscle ◽  
Sodium Channels ◽  
Local Anesthetics ◽  
Frog Skeletal Muscle ◽  
Abrupt Increase ◽  
Frequency Dependent ◽  
Temperature Changes ◽  
Influence Of Temperature ◽  
Lipid Environment ◽  
Frequency Of Stimulation

The potency of various types of alkyl amphipathic (cationic, anionic, and neutral) as well as tertiary amine local anesthetics in impairing the excitability of frog skeletal muscle was markedly enhanced by an increase in temperature from 20 to 30 °C. Enhancement of the local anesthetic effects of all types of agents was also produced by a decrease in temperature to 5 °C, but this effect was found to be frequency dependent. With abrupt increase or decrease in temperature, changes in excitability were rapid and unlikely to be the result of changes in the partition of the apolar portions of these molecules into the hydrophobic regions of the sarcolemma. These results are interpreted as indicating that both the presence of local anesthetics and alterations in temperature can influence the rates of potential-dependent changes in the conformation of membrane proteins that control the permeability of excitable sodium channels, possibly by modifying the fluidity of specific portions of their hydrophobic components or their immediate lipid environment. The accumulation of inactivation as the result of incomplete recovery from the effects of preceding depolarizations appears sufficient to explain the frequency-dependent effects produced by these agents.

Inhibition of frog skeletal muscle sodium channels by newly synthesized chiral derivatives of mexiletine and tocainide

1997 ◽  
Vol 356 (6) ◽  
pp. 777-787 ◽  
Author(s):  
Annamaria De Luca ◽  
Fedele Natuzzi ◽  
Giulia Falcone ◽  
Andrea Duranti ◽  
Giovanni Lentini ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Sodium Channels ◽  
Frog Skeletal Muscle ◽  
Derivatives Of

Blockade of sodium channels by bistramide A in voltage-clamped frog skeletal muscle fibres

1992 ◽  
Vol 1103 (1) ◽  
pp. 109-114 ◽  
Author(s):  
Martin-Pierre Sauviat ◽  
Danièle Gouiffes-Barbin ◽  
Eudes Ecault ◽  
Jean-Francois Verbist
Keyword(s):  
Skeletal Muscle ◽  
Sodium Channels ◽  
Muscle Fibres ◽  
Frog Skeletal Muscle ◽  
Bistramide A ◽  
Skeletal Muscle Fibres

Ultra-Rapid Freezing of Isolated Skeletal Muscle Fibers

1977 ◽  
Vol 35 ◽  
pp. 576-577
Author(s):  
Joachim R. Sommer ◽  
Nancy R. Wallace
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Granular Material ◽  
Nuclear Envelope ◽  
Intracellular Calcium ◽  
Ruthenium Red ◽  
Threshold Concentration ◽  
Rapid Freezing ◽  
Frog Skeletal Muscle ◽  
Electrical Isolation

After Howell (1) had shown that ruthenium red treatment of fixed frog skeletal muscle caused collapse of the intermediate cisternae of the sarcoplasmic reticulum (SR), forming a pentalaminate structure by obi iterating the SR lumen, we demonstrated that the phenomenon involves the entire SR including the nuclear envelope and that it also occurs after treatment with other cations, including calcium (2,3,4).From these observations we have formulated a hypothesis which states that intracellular calcium taken up by the SR at the end of contraction causes the M rete to collapse at a certain threshold concentration as the first step in a subsequent centrifugal zippering of the free SR toward the junctional SR (JSR). This would cause a) bulk transport of SR contents, such as calcium and granular material (4) into the JSR and, b) electrical isolation of the free SR from the JSR.

Electron Probe Analysis of Muscle

1982 ◽  
Vol 40 ◽  
pp. 398-401
Author(s):  
A. V. Somlyo ◽  
H. Shuman ◽  
A. P. Somlyo
Keyword(s):  
Skeletal Muscle ◽  
Smooth Muscle ◽  
Sarcoplasmic Reticulum ◽  
Resting State ◽  
Binding Sites ◽  
Electron Probe ◽  
Frog Skeletal Muscle ◽  
Electron Probe Analysis ◽  
Probe Analysis

Electron probe analysis of frozen dried cryosections of frog skeletal muscle, rabbit vascular smooth muscle and of isolated, hyperpermeab1 e rabbit cardiac myocytes has been used to determine the composition of the cytoplasm and organelles in the resting state as well as during contraction. The concentration of elements within the organelles reflects the permeabilities of the organelle membranes to the cytoplasmic ions as well as binding sites. The measurements of [Ca] in the sarcoplasmic reticulum (SR) and mitochondria at rest and during contraction, have direct bearing on their role as release and/or storage sites for Ca in situ.

Sign in / Sign up

Export Citation Format

Share Document