[Effect of imidapril on the effective refractory period and sodium current of ventricular noninfarction zone in healed myocardial infarction].
OBJECTIVE
To investigate the effects of imidapril (IMI) on effective refractory period (ERP) and sodium current (I(Na)) of myocytes in ventricular noninfarction zone of healed myocardial infarction (HMI) in rabbit models.


METHODS
Rabbits with left coronary artery ligation were prepared and IMI (0.625 mg x kg(-1) x d(-1), 8 weeks) was orally administered. The ERP and sodium current were recorded.


RESULTS
The ERP in HMI heart was prolonged. The ERP in IMI group was lower significantly than that of HMI group. The I(Na) density of myocyte in HMI ventricle decreased obviously. V 1/2 of steady state inactivation of I(Na) shifted to hyperpolarization, and time constant (tau) of recovery from inactivation in HMI ventricular myocyte was longer than that of sham ventricular myocyte. I(Na) density in IMI group increased markedly as compared with that of HMI group.


CONCLUSIONS
IMI was shown to reverse the abnormal prolongation of ERP in rabbit heart with the HMI and increase I(Na) density. It may be the mechanism of IMI preventing against antiarrhythmia in healed myocardical infarction.
Li
Yang
Y
Institute of Geriatric Cardiology of Chinese PLA General Hospital, Beijing 100853, China. liyangbsh@163.com
Niu
Hui-Yan
HY
Liu
Nian
N
Zhang
Cun-Tai
CT
Lu
Zai-Ying
ZY
Wang
Shi-Wen
SW
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D000818:Animals; D015220:Calcium Channels / Q000378:metabolism*; D005260:Female; D006352:Heart Ventricles / Q000166:cytology; D048289:Imidazolidines / Q000494:pharmacology*; D008297:Male; D009203:Myocardial Infarction / Q000378:metabolism / Q000503:physiopathology; D032383:Myocytes, Cardiac / Q000378:metabolism; D011817:Rabbits; D012032:Refractory Period, Electrophysiological / Q000187:drug effects*
D000806:Angiotensin-Converting Enzyme Inhibitors; D015220:Calcium Channels; D048289:Imidazolidines; C065166:imidapril