OBJECTIVETo study the effect of deoxynivalenol (DON), a mycotoxin produced by Fusarium graminearum, on action potentials of cultured cardiomyocytes and the possible protective effects of sodium selenite.

METHODSVentricular myocytes from neonatal Wistar rats were cultured, and the transmembrane action potentials were recorded with glass microelectrodes before and after addition of DON at different concentrations. The cultured cardiomyocytes were pretreated with 0.5 mg/L selenium (as sodium selenite) to observe the protective effects of selenium against the effects of DON.

RESULTSDON at concentrations of 50, 100 and 200 mg/L decreased the action potential parameters including action potential amplitude (APA), overshoot (OS), threshold potential (TP), maximum rate of depolarization (Vmax) and action potential discharging frequency (APF), and prolonged the action potential duration of 10%, 50% and 90% repolarization (APD(10), APD(50) and APD(90)). Some of the parameters, such as APA, Vmax, APD and APF, changed in a concentration-dependent manner. The cultured cardiomyocytes pretreated with 0.5 mg/L of selenium for about 16 h presented only slight changes in action potential parameters induced by 200 mg/L DON.

CONCLUSIONSDON inhibit the membrane action potentials of cardiomyocytes, suggesting DON may interfere with the transmembrane movement of Ca(2+) and K(+), and sodium selenite may decrease the toxic effect of DON on cultured cardiomyocytes.