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 µmol/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 µmol/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.