Research progress on nitric oxide depletion and its replacement therapy in intravascular hemolytic diseases

In the case of intravascular hemolysis in patients with hemolytic diseases such as paroxysmal nocturnal hemoglobinuria (PNH) and sickle cell disease (SCD), patients′ body can produce a large amount of free hemoglobin (FHb) and release intracellular arginase. FHb can rapidly scavenge nitric oxide (NO) and arginase can degrade L-arginine, which is substrate for NO synthesis. All together with the increased amount of reactive oxygen species (ROS) after hemolysis, NO appears to be depleted in the circulation, which results damages to endothelial and dysfunction of microcirculation, as well as eventually lead to acute and chronic impair to multiple organs. In recent years, with the in-depth study of the mechanisms beneath NO depletion in intravascular hemolytic disorders, the common pathological mechanisms of such diseases have been elucidated, and NO replacement therapy seems to be an all new approach. In view of this, this article reviews the research progress in the field of NO depletion and its replacement therapy in intravascular hemolytic diseases. Key words: Hemolytic disease; Nitric oxide; Depletion; Replacement therapy; Intravascular hemolysis