Effects of allitridum on the transient outward potassium current in rats with heart failure.

Objective To study the effect of allitridum on the transient outward potassium current (I-to) of ventricular myocytes in heart failure (HF). Methods The dual enzymatic method was used to separate single ventricular myocytes from Sprague Dawley rats. Patch-clamping was used to record I-to and analyze the effect of allitridum on the current. Results The I-to current had a significant decrease in the HF group, compared with the control group. The density of I-to in the HF group was increased after treatment of allitridum (30 mu mol/L). The peak current densities of I-to were enhanced in the HF group from 6.01 +/- 0.30 pA/pF to 8.41 +/- 0.54 pA/pF (P < 0.01) at + 50 mV after treatment with allitridum (30 mu mol/L). We also determined the effect of allitridum on the gating mechanism of the I-to in the HF group. Conclusions We found that allitridum increased the I-to by accelerating the activation of channels and shortened the time constants of inactivation, and allitridum decreased the remodeling of I-to in ventricular myocytes of rats with HF.