[Effects and high and low doses of vitamin A on the excitability of frog cardiomyocytes].
The effects of the vitamin A lysosomal membrane labilizator on electrophysiological characteristics was investigated on frog cardiomyocytes. Large and small doses of vitamin A produced qualitatively identical effects: decrease of the steepness of action potential (AP) front, decrease of the spike amplitude, shortening of the plateau, decrease of the steepness in the last phase of AP-repolarization. The AP-duration decreased considerably. Large doses of the vitamin also reduced the rest potential level and insignificantly increased the heart contractions frequency. We assume that vitamin A can affect the cardiomyocyte surface membrane permeability, thereby decreasing its excitability due to suppression of the sodium and potassium.
Satybaldina
N K
NK
Frolov
V A
VA
D000200:Action Potentials; D000818:Animals; D002199:Capillary Permeability; D002462:Cell Membrane / Q000187:drug effects; D006321:Heart / Q000187:drug effects* / Q000502:physiology; D066298:In Vitro Techniques; D008564:Membrane Potentials; D009200:Myocardial Contraction / Q000187:drug effects; D009206:Myocardium / Q000166:cytology* / Q000378:metabolism; D011188:Potassium / Q000378:metabolism; D011896:Rana temporaria; D012964:Sodium / Q000378:metabolism; D014801:Vitamin A / Q000008:administration & dosage / Q000494:pharmacology*
D014801:Vitamin A; D012964:Sodium; D011188:Potassium
Vliianie bol'shikh i malykh doz vitamina A na vozbudimost' kardiomiotsitov liagushki.