[The effects of urea on ECG and the sodium currents of ventricular myocyte in mice].

To observe the effects of urea on ECG and sodium currents of ventricular myocyte in mice. ECG and patch clamp techniques were used in the experiments, to record ECG of mice and sodium currents of ventricular myocyte in mice. Urea could lead mice heart rate evidently slow down (P < 0.01) with concentration dependent. The heart rate were (556 +/- 29, 469 +/- 37, 378 +/- 48) b minT in low, middle, high groups respectively before using urea and (612 +/- 27, 615 +/- 23, 619 +/- 26) x min(-1) after. The conduction block arrhythmia was happened in middle and high groups. The sodium currents of ventricular myocyte in mice was inhibited by urea(P < 0.05). The sodium currents amplitude value were reduced to (7.32 +/- 0.68, 5.69 +/- 0.64, 4.58 +/- 0.57) nA after using urea in each group and were (8.76 +/- 0.91, 8.87 +/- 1.01, 8.77 +/- 0.96) nA before, submit concentration dependent. Urea can inhibit the sodium currents of ventricular myocyte in mice to make it happen conduction block arrhythmia.