[Protective effects of losartan against myocardial ischemic reperfusion in intact canine].
OBJECTIVE
To evaluate the protective effect of losartan, an angiotensin II type 1 (AT1) receptor antagonist, against myocardial ischemic reperfusion in intact canine.


METHODS
Sixteen dogs were divided into model group(n=8) with left anterior descending coronary artery occlusion for 30 min followed by reperfusion for 30 min and losartan group (n=8) with 5 mg/(kg x d) intragastric losartan administration for 2 weeks before the ischemic-reperfusion model establishment. Monophasic action potential recording technique was employed to observe the incidence of early after depolarization (EAD) and reperfusion arrhythmias.


RESULTS
In the model group, 5 dogs (62.5%) developed EAD and reperfusion arrhythmia while 3 (37.5%) developed the symptoms in losartan group, showing significant difference between the two groups (P<0.05). No ventricular tachycardia or ventricular fibrillation was observed in losartan group (P<0.01).


CONCLUSIONS
Losartan can suppress the occurrence of EAD during reperfusion following myocardial ischemia to reduce the incidence of reperfusion arrhythmias, suggesting its protective effect against myocardial ischemic injury.
Yang
Yun
Y
Department of Cardiology, People's Hospital of Taiping, Dongguang 523900, China.
Huo
Zhi-cheng
ZC
Peng
Jian
J
Jia
Man-ying
MY
Huang
Zheng
Z
Wang
Zhi-ming
ZM
Chen
Yu-lan
YL
D047228:Angiotensin II Type 1 Receptor Blockers / Q000494:pharmacology / Q000627:therapeutic use*; D000818:Animals; D004285:Dogs; D004594:Electrophysiology; D005260:Female; D019808:Losartan / Q000494:pharmacology / Q000627:therapeutic use*; D008297:Male; D009203:Myocardial Infarction / Q000188:drug therapy*; D015428:Myocardial Reperfusion Injury / Q000517:prevention & control*
D047228:Angiotensin II Type 1 Receptor Blockers; D019808:Losartan