Effects ofAcuteCellular Injury on Coronary Vascular Reactivity inAwakeDogs

SUMMARY The study wasdesigned to examine effects of acute cellular injury on regional myocardial blood flow (RMBF)and cor- onary vascular reactivity. Before myocardial infarction in 14 dogs,RMBFwas measured using 7-lO,u microspheres during the hyper-emic response following a 60 sec transient ischemic stimulation(TIS). Myocardial infarction wasinducedbycomplete occlusion for two hours and then inflow to the injured area was re-established.RMBF was measured four hours later during basal conditions,following a 60 sec TIS and during infusion of adenosine, 1.0mg/kg/min. Effects ofacute cellular injury were examinedby mea- suring RMBFin multiple myocardial samples,grouped according to ISCHEMIA OFTHE MYOCARDIUM sufficient to ini-tiate acute myocardial injury effects local responses in thezone of ischemia which directly alter tissue perfusion.1-5 Studies from this laboratory6 have demonstrated that thealterations in regional myocardial perfusion which result from acutecellular injury are directly proportional