Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Sodium currents (INa) and asymmetrical displacement currents (ID) were measured in the same nerve fibres from Rana esculenta under similar conditions. 2. For exploring possible kinetic and steady state relations between INa and ID the following quantities were compared: (i) the activation of the sodium channels and (ii) the charge displacement of ID. 3. The delay of sodium activation increased after hyperpolarization. A corresponding effect on the displacement of charge was not observed. 4. Upon a small depolarization sodium activation rose slower than the displacement of charge, whereas at large depolarizations sodium activation reached a steady level before the charge displacement. 5. Upon repolarization to various levels between -52 and 12 mV relative to the resting potential, the ratio between the time constants of charge displacement and of sodium tail current varied between 3 and 1. 6. In the steady state the sodium activation was one half at about the same potential as the charge displacement but exhibited a clearly steeper voltage dependence. 7. Blocage of sodium channels with tetrodotoxin did not affect the asymmetrical displacement current. Replacing a part of external Na by tris did not alter the sodijm activation process. 8. The results indicate that the asymmetrical displacement of charge may reflect states of the gating mechanism in sodium channels but cannot be considered as a correlate of the Hodgkin Huxley m variable.
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PMID:Asymmetrical displacement current and its relation with the activation of sodium current in the membrane of frog myelinated nerve. 108 37

Voltage clamp experiments were made on ezymically isolated and internally perfused rat cardiac cells. The effect of a diethylamine analog of ethmozine (DAAE) on sodium current (INa) was tested when the drug was applied inside or outside the cell. It was found that the effect of DAAE (8 X 10(-6) g/ml) on INa was asymmetrical: after DAAE addition outside the cell, the amplitude of INa was effectively suppressed. Thus, 5 minutes after DAAE action the maximal value of INa in a voltage-current relationship was 20% of the control value without significant changes in the kinetics of INa. When the DAAE was added inside the cell preferentially, the inactivation time constant was increased without significant changes in the amplitude of the maximal INa. The same results were obtained with pronase (1 mg/ml) added inside the cell. It was supposed that as compared to ethmozine, the DAAE possesses a supplementary binding site on the cardiac cell membrane possibly linked to the structures responsible for inactivation processes.
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PMID:[Effect of diethylamine analog of ethmozine on parameters of sodium current in isolated rat cardiomyocytes]. 629 14