Peroxynitrite-induced hemolysis of human erythrocytes and its inhibition by antioxidants.

It was found that human erythrocytes underwent hemolysis when incubated with peroxynitrite at 37 degrees C under air. The extent of hemolysis increased with increasing peroxynitrite concentration and decreasing hematocrit. The peroxynitrite-induced hemolysis was suppressed only partially by a radical scavenging antioxidant such as uric acid and Trolox, a water-soluble vitamin E analogue, but reduced glutathione, N-acetylcysteine and albumin efficiently inhibited the hemolysis. A selenium-containing organic compound, ebselen, also suppressed the hemolysis. On the other hand, nitric oxide and superoxide generated concomitantly from 3-morpholinosydnonimine (SIN-1) did not induce appreciable hemolysis, while it converted hemoglobin to methemoglobin extensively.