Increased myocardial infarct size because of reduced coronary collateral blood flow in beagles

Abstract

Effects of permanent left circumflex coronary artery occlusion (CAO) were examined in conscious purebred beagles and mongrel dogs, instrumented with miniature left ventricular (LV) pressure gauges, wall thickness gauges in the ischemic zone, catheters in left atrium and aorta, and snares around the left circumflex coronary artery. Blood flow was measured using the radioactive microsphere technique before CAO and at 5 min, 1, 3, and 24 h after CAO. Although CAO reduced myocardial blood flow similarly in beagles and mongrels, significantly less (P less than 0.05) recovery of myocardial blood flow was observed over the following 24-h period in beagles. Infarct size, as determined by triphenyltetrazolium chloride and expressed as percentage of area at risk, was larger (P less than 0.05) in beagles (62.0 +/- 5.1%) than mongrels (42.5 +/- 4.2%). Thus beagles do not tolerate ischemia as well as mongrel dogs and possess fewer functional coronary collaterals resulting in larger infarcts after CAO.

Insights in animal models for translational cardiovascular research：A pharmaceutical industry perspective

“…Additionally, infarct size differs among species and among lines of the same species in this model. For instance, beagle dogs have a larger infarct size than mongrel dogs (Uemura et al, 1989). Other studies that examined obese Ossabaw swine by LCx ameroid constrictor placement resulted in a model of chronic ischemia as opposed to MI-induced HF because no or minimal subendocardial signs of infarction were observed (Elmadhun, Lassaletta, Chu, & Sellke, 2013).…”