Author + information
- Received April 17, 1991
- Revision received June 13, 1991
- Accepted July 10, 1991
- Published online January 1, 1992.
- Mervyn B. Forman, MD, PhD, FACC1,∗,1,
- Christos J. Pitarys II, MD1,
- Harry D. Vildibill, BS1,
- Thomas L. Lambert, MD1,
- David A. Ingram, BS1,
- Renu Virmani, MD, FACC1,∗,2 and
- John J. Murray, MD, PhD1
- ↵∗Address for reprints: Mervyn B. Forman, MD, Division of Cardiology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-2170.
Previous studies have demonstrated that intravenous administration of large doses of Fluosol, a perfluorochemical preparation, reduced infarct size 24 h after reperfusion, an effect that was associated with reduced neutrophil infiltration. The effect of a clinically tolerable dose of Fluosol on infarct size after a prolonged period of reperfusion and its mechanism of action on neutrophils remain unknown.
Twenty-one anesthetized closed chest dogs were subjected to 90 min of proximal left anterior descending coronary artery occlusion and 72 h of reperfusion. An additional five dogs that did not undergo regional myocardial ischemia were utilized to explore the mechanism of action of Fluosol on neutrophil function. In the infarct study, animals were randomized to receive either intravenous Fluosol (n = 10) or an equivalent volume of Ringer's lactate solution (control; n = 11) at 15 ml/kg body weight during the last 30 min of occlusion and for the 1st 30 min of reperfusion
Fluosol significantly reduced infarct size when expressed as percent area at risk 72 h aller reperfusion (13.7 ± 2.7% vs. 38.3 ± 4.5%, respectively, p < 0.001). This reduction was associated with significant improvement in regional wall motion (18.4 ± 2.3% vs. 5.5 ± 2%, p < 0.001). Endocardial blood fiow in the ischemic bed was significantly higher 3 h after reperfusion in Fluosol-treated dogs (0.63 ± 0.08 vs. 0.34 ± 0.07 ml/min per g, p = 0.01). Reduced capillary plugging by neutrophils with relative preservation of endothelial cell structure was observed in Fluosol-treated animals. Infusion of Fluosol produced a marked transient decrease in peripheral neutrophil and platelet counts in both ischemic and nonischemic dogs and was associated with a significant reduction in total hemolytic complement levels. Studies of neutrophil function ex vivo revealed a reduction in chemotaxis and lysozyme degranulation after infusion of Fluosol. In vitro experiments showed that Fluosol produced a rapid and sustained activation of neutrophils determined by superoxide anion production.
These data demonstrate that low dose intravenous Fluosol produces a sustained reduction in infarct size in the canine model. The beneficial effect may be in part due to the suppression of various neutrophil functions in the reperfused myocardium subsequent to peripheral activation by Fluosol. Such interventions may offer a novel therapy to enhance myocardial salvage by sequestration of circulating neutrophils during the critical early reperfusion period.
↵1 Dr. Forman is a recipient of a First Award from the National Institutes of Health.
↵2 Dr. Murray is an RJR Nabisco Scholar, RJR Nabisco, Winston-Salem, North Carolina.
☆ This study was supported in part by Grant R01 MC 40829-011 from the National Institutes of Health, Bethesda, Maryland and Alpha Therapeutic Corporation, Los Angeles, California.
☆☆ This study was presented in part at the 62nd Scientific Session of the American Heart Association, November 1989.
- Received April 17, 1991.
- Revision received June 13, 1991.
- Accepted July 10, 1991.