Changes of potassium currents in rabbit ventricle with healed myocardial infarction / 中国病理生理杂志

ABSTRACT

AIM: To elucidate the mechanism of arrhythmia in healed myocardial infarction (HMI), and to investigate the changes of action potential duration (APD),transient outward potassium current (I to ), delayed rectifier potassium current (I K) and inward rectifier potassium current (I K1 ) of left ventricular myocytes in noninfarcted zone of HMI. METHODS: 12 rabbits were randomly assigned in two groups HMI group (thoracotomy and ligation of the circumflex coronary); sham-operated group (thoracotomy but no conorary ligation). 3 months after operation, whole cell patch clamp technique was used to record APD, I to , I K and I K1 of ventricular myocytes in non-infarcted zone. RESULTS: Membrane capacitance was larger in HMI group than that in sham-operated group. Action potential duration was lengthened significantly in HMI group and early after depolarization (EAD) appeared in HMI group. The densities of I to , I K,tail and I K1 were reduced significantly in HMI group (P