LAZAROIDS, 21-aminosteroids lacking steroid activity have cytoprotective properties against iron-dependent lipid peroxidation. 1 In addition to their antioxidant properties, lazaroids exert their cytoprotective effect by inhibiting arachidonic acid release, membrane stabilization, suppression of Kuppfer cell activation, and down-regulation of cytokine expression and release. 1-3 While previous reports have shown that lazaroids are effective in reducing ischemia and reperfusion injury to many different organ systems, there have been conflicting reports of the potency of the various lazaroid compounds. 4 In this study, we examined the potency and effectiveness of the three major lazaroid compounds in protecting organs against ischemia and reperfusion injury. RESULTS Except for Group A1, the lazaroid infusion was well tolerated. Infusion of lazaroid A1 (high dose) was associated with arrhythmia and hypotension. Two-week animal survival in the control group (30%) was significantly worse than the treated groups (all but one treated