Introduction: Nitric oxide donor, L-Arg, has been reported to be beneficial in preserving tissue viability following ischemia-reperfusion. The homeostasis of L-arginine is regulated through 2 enzyme systems. The purpose of this project was to evaluate roles of agmatine and L-Arg in IR injury.

Methods: 80 rats were assigned to following 8 groups (1)sham (2) sham+L-Arg; (3) sham+1400W; (4) sham + Agmatine; (5) IR + saline; (6) IR + L-Arg; (7) IR+ 1400W; (8)IR + Agmatine. The gracilis muscle was elevated and the contralateral femoral vein exposed. Groups 1, 2 ,5, 6 received either saline or L-Arg 5 minutes before to 40 minutes following reperfusion. Groups 3, 4, 7, 8 received either 1400w or agmatine 10 minutes prior to reperfusion. At 24 hours, the gracilis muscles were harvested and stained with NBT. Percent muscle necrosis was measured.

Resutls: There was a significant decrease in necrosis in groups 6,7,and 8 versus 5. In addition, there was a significant decrease in necrosis between groups 7 and 8 versus 6.

Conclusion: These results indicate that agmatine plays a cytoprotective role in IR injury. The lack of statistical significance between groups 7 and 8, indicate that agmatine may have a direct effect on iNOS inhibition.