Redox state potential influences (+/-) delta [Na+]o activity values during acetylcholine contractures of frog skeletal muscles.
1. The slow alterations in the activity of extracellular Na+ concentrations were measured by using ion-selective electrodes. 2. In the first min there is an increase in the changes of the activity of extracellular Na+ following acetylcholine evoked contractures. 3. This increment was significantly inhibited by k-Strophantoside application, suggesting an active transport origin of this first peak. 4. In the second min a strong decrease in the activity of extracellular Na+ concentration followed. 5. Reducing agent (ascorbate) increased, while oxidant (methylene-blue) decreased both the first increment and the sequential decrement in the activity of the extracellular Na+ concentrations. 6. On the basis of these experiments a site of action of the redox regulation of excitatory processes could be the modification of Na+ fluxes.
D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D066298:In Vitro Techniques; D007328:Insulin / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects*; D010084:Oxidation-Reduction; D011893:Rana esculenta; D012964:Sodium / Q000378:metabolism*; D013328:Strophanthins / Q000494:pharmacology
D007328:Insulin; D013328:Strophanthins; D012964:Sodium; D000109:Acetylcholine; C029082:strophanthin K