Alteration of transient outward potassium current in ventricular myocytes from 1-week and 2-month infarcted rabbit hearts / 中国病理生理杂志

ABSTRACT

AIM: To study the current density of transient outward potassium current (I_(to)) in cells from the epicardial zone of the 1-week and 2-month infarcted rabbit heart. METHODS: Rabbits were infarcted by ligation of the left anterior descending coronary artery, 1 week as well as 2 months later, the single ventricular myocytes were isolated enzymatically from the infracted area of 1-week infracted rabbit heart (PMI-1 week) and 2-month infracted heart (PMI-2 months), region remote from the infracted zone of 2-month infracted heart (REM-2 months) and free wall of left ventricule from noninfarcted heart (CON). I_(to) was recorded using whole cell patch-clamp techniques. (RESULTS:) Membrane capacitance of myocytes in REM-2 months group was signifitantly larger than that in CON. I_(to)current density (at +60 mV) was significantly reduced in PMI-1 week [(7.5?2.4) pA/pF, n=12] and PMI-2 months [(10.6?4.1) pA/pF, n=18] compared with CON [(17.4?5.2) pA/pF, n=16], P