Arrhythmias and alterations in autonomic nervous function induced by deoxynivalenol (DON) in unrestrained rats

This study aimed to determine the cardiac and autonomic nervous effects of deoxynivalenol (DON), a representative mycotoxin which frequently contaminates cereal grains, in conscious rats that had been implanted with telemetric transmitters. Four groups of rats given subcutaneous injections of 0.5, 1.0, or 2.0 mg/kg of DON or propylene glycol (vehicle solution) were used in the experiments. Telemetric electrocardiogram (ECG) recordings were performed for 2 weeks or longer during the pre- and post-DON injection period. The present study demonstrated that DON caused marked arrhythmias, such as second-degree atrioventricular block, atrial bradycardia, supraventricular extrasystole, and ventricular extrasystole, at 3 hr or later (mostly at 10-20 hr) after the DON-injection, which were accompanied by a significant increase in heart rate (HR) and a significant decrease in total power and low- and high-frequency power during the period from 90 to 180 min after the injection. In conclusion, it was elucidated that DON produces significant cardiac dysfunction and transient inhibition of the autonomic nervous function in conscious rats at a dose of 0.5 mg/kg s.c. or more.