N-acetylcysteine attenuates leukocytic inflammation and microvascular perfusion failure in critically ischemic random pattern flaps

Introduction: Microcirculatory dysfunction causes ischemia resulting in tissue necrosis. N-acetylcysteine (MAC) has been shown capable of protecting tissue from ischemic necrosis. However, the mechanism of action of MAC is yet not fully understood. Objective: Herein, we studied whether NAC is capable of attenuating microvascular perfusion failure in critically ischemic musculo-cutaneous tissue. Material and methods: A laterally based skin flap was elevated in the dorsum of C57BL/6 mice and fixed into a dorsal skinfold chamber. Arteriolar perfusion, functional capillary density, leukocytic inflammation, apoptotic cell death, and non-perfused tissue area were repetitively analyzed over 10 days by intravital fluorescence microscopy. Treatment with either 100 mg/kg NAC or saline (control) was started 30 min before surgery and was continued until day 10 after flap elevation. Results: Surgery induced leukocytic inflammation, microvascular perfusion failure, apoptosis, and tissue perfusion failure. NAC was capable of significantly attenuating the area of non-perfused tissue. This was associated by a marked arteriolar dilation and an increased capillary perfusion. MAC further reduced the ischemia-associated leukocytic response and significantly attenuated apoptotic cell death in all areas of the flap. Conclusion: NAC is effective to attenuate leukocytic inflammation and microvascular perfusion failure in critically ischemic tissue. Thus. NAC treatment may represent a promising approach to improve the outcome of ischemically endangered flap tissue. (C) 2011 Elsevier Inc. All rights reserved.