PS208. Edaravone Injected at the Start of Reperfusion Reduces Muscle Injury following Leg Ischemia in Rats

Abstract

At VAM 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. 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. 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 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 < .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 < .001, Fig, original 200x). 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.