Microvascular reperfusion injury: rapid expansion of anatomic no reflow during reperfusion in the rabbit.
The aim was to define the degree and time course of reperfusion-related expansion of no reflow. In five groups of anesthetized, open-chest rabbits (30-min coronary occlusion and different durations of reperfusion), anatomic no reflow was determined by injection of thioflavin S at the end of reperfusion and compared with regional myocardial blood flow (RMBF; radioactive microspheres) and infarct size (triphenyltetrazolium). The area of no reflow progressively increased from 12.2 +/- 4.2% of the risk area after 2 min of reperfusion to 30.8 +/- 3.1% after 2 h and 34.9 +/- 3.3% after 8 h and significantly correlated with infarct size after 1 h of reperfusion (r = 0.88-0.97). This rapid expansion of no reflow predominantly occurred during the first 2 h, finally encompassing approximately 80% of the infarct size, and was accompanied by a decrease of RMBF within the risk area, being hyperemic after 2 min of reperfusion (3.78 +/- 0.75 ml x min(-1) x g(-1)) and plateauing at a level of approximately 0.9 ml x min(-1) x g(-1) by 2 and 8 h of reperfusion (preischemic RMBF: 2.06 +/- 0.01 ml x min(-1) x g(-1)). The development of macroscopic hemorrhage lagged behind no reflow, was closely correlated with it, and may be the consequence of microvascular damage.
Reffelmann
Thorsten
T
The Heart Institute, Good Samaritan Hospital, University of Southern California, Los Angeles, California 90017-2395, USA.
Kloner
Robert A
RA
D000818:Animals; D052160:Benzothiazoles; D003326:Coronary Circulation / Q000502:physiology*; D005456:Fluorescent Dyes / Q000493:pharmacokinetics; D006470:Hemorrhage / Q000503:physiopathology; D008297:Male; D008833:Microcirculation / Q000502:physiology; D009203:Myocardial Infarction / Q000473:pathology / Q000503:physiopathology*; D015425:Myocardial Reperfusion; D015428:Myocardial Reperfusion Injury / Q000473:pathology / Q000503:physiopathology*; D011817:Rabbits; D013844:Thiazoles / Q000493:pharmacokinetics
D052160:Benzothiazoles; D005456:Fluorescent Dyes; D013844:Thiazoles; C009462:thioflavin T