OBJECTIVETo compare the acute myocardial infarction models in Beagle dogs and mongrel dogs, and study whether the Beagle dog model is sensitive to drug intervention.

METHODThe acute myocardial infarction model of dog was set up through ligation of anterior descending branch of coronary artery in dogs, in order to observe morphological changes of the heart and determine artery length and heart coefficient of exposed anterior descending branch of coronary artery. The epicardium electrocardiogram (sigmaST, N-ST) was used to measure the degree of myocardial ischemia. The quantitative histological assay (nitroblue tetrazolium, N-BT stain) was adopted to determine the area of myocardial infarction.

RESULTThere was no significant difference between Beagle dogs and mongrel dogs in terms of sigmaST, N-ST and ischemia area. The diltiazem group of Beagle dogs showed obvious reduction in the ischemia area (P < 0.05 and P < 0.01), with notable decline in sigmaST and N-ST, however, it had no statistical difference compared with the Beagle dog model group. Beagle dogs had clear coronary branches, longer exposed arteries and less difference in organ coefficient, which were suitable for the preparation of the myocardial infarction model, whereas mongrel dogs had irregular coronary branches and exposed arteries, with greater individual difference.

CONCLUSIONBeagle dogs are superior to mongrel dogs in the preparation of the acute myocardial infarction model, which is sensitive to for drug intervention.