Redox activity of cell-free hemoglobin: Implications for vascular oxidative stress and endothelial dysfunction

Abstract

Cell-free hemoglobin (Hb) outside the natural protective environment of the red blood cell (RBC) can undergo uncontrolled redox transformations to non-functional and/or toxic protein-bound and unbound species. Understanding the impact of Hb redox activity on vascular endothelial integrity and function remains a critical factor in the development of safe and efficacious acellular Hb-based oxygen therapeutics. This chapter will provide an overview of Hb redox reactions and their propensity to generate oxidative stress in the vascular system. Specific emphasis will be placed on studies from our laboratory that link oxidative stress with the development of endothelial dysfunction in cell culture systems and in animal models.