Microvascular reperfusion injury: rapid expansion of anatomic no reflow during reperfusion in the rabbit

Am J Physiol Heart Circ Physiol. 2002 Sep;283(3):H1099-107. doi: 10.1152/ajpheart.00270.2002.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Benzothiazoles
  • Coronary Circulation / physiology*
  • Fluorescent Dyes / pharmacokinetics
  • Hemorrhage / physiopathology
  • Male
  • Microcirculation / physiology
  • Myocardial Infarction / pathology
  • Myocardial Infarction / physiopathology*
  • Myocardial Reperfusion
  • Myocardial Reperfusion Injury / pathology
  • Myocardial Reperfusion Injury / physiopathology*
  • Rabbits
  • Thiazoles / pharmacokinetics

Substances

  • Benzothiazoles
  • Fluorescent Dyes
  • Thiazoles
  • thioflavin T