Do beagles have different myocardial blood flow recovery and infarct size compared to mongrel dogs after permanent coronary artery occlusion?
Beagles possess fewer functional coronary collaterals than mongrel dogs, resulting in less blood flow recovery and larger infarcts after coronary occlusion, which is an important consideration for selecting animal models in ischemia research.
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.
Uemura et al. (Fri,) studied this question.