Abstract 227: Edaravone Injected at the Start of Reperfusion Reduces Muscle Injury Following Leg Ischemia in Rats
Introduction & Hypothesis: It is well known that free radicals cause reperfusion injury after leg ischemia. At ATVB 2010 & 2011, we have reported that preoperative injection of the free-radical scavenger, edaravone (Radicut®, Mitsubishi Tanabe Pharma Co., Japan) prevented reperfusion injury. In this study, we evaluated whether edaravone can reduce reperfusion injury if injected at the start of reperfusion.
Methods: Male Lewis rats (525 ± 78 g, n = 10) were subjected to reperfusion injury models by clamping the bilateral common femoral arteries for 5 hours followed by de-clamping. Rats were divided into two groups and intraperitoneally injected with edaravone (group edaravone; 9.0 mg / kg, n = 5) or saline (control group; n = 5) at the same time as removing the clamps (i.e., the start of reperfusion). Five hours after de-clamping, the muscles of lower extremity were harvested. Tissues were stained with hematoxylin & eosin (HE), in order to count the viable muscle cells. They were also stained with periodic acid-Schiff (PAS), in order to assess the glycogen storage in muscle cells. The number of viable muscle cells and the percentages of PAS-positive area were measured on each three different field (original magnification 200x).
Results: In the control group, most of the muscle cells were swelling. The density of viable muscle cells in the group edaravone was significantly greater than that of control group (593±60 cells/mm2 vs. 258±31 cells/mm2, p < 0.01). The mean percentage of PAS-positive area in the edaravone group was also significantly higher than that in control group (30.1 ± 6.9 % vs. 7.3 ± 2.1%, p < 0.001, Figure attached).
Conclusions: Our results suggest that edaravone injected at the start of reperfusion can also reduce muscle injury following leg ischemia in rats, storing a high level of glycogen in viable muscle cells. Therefore, edaravone might be useful in clinical settings following leg ischemia.
- © 2012 by American Heart Association, Inc.