title: Decreased survival in vivo of diamide-incubated dog erythrocytes. A model of oxidant-induced hemolysis.
abstract: Erythrocytes from patients with chronic hemolytic variants of glucose-6-phosphate dehydrogenase (G-6-PD) deficiency have structural membrane protein abnormalities accompanied by decreased cell membrane deformability which we postulate represent the consequences of oxidant-induced membrane injury. To evaluate the pathophysiologic significance of oxidant-induced membrane injury, we studied the in vitro and in vivo effects of the thiol-oxidizing agent, diamide, on dog erythrocytes. In vitro incubation of dog erythrocytes with 0.4 mM diamide in Tris-buffered saline for 90 min at 37 degrees C resulted in depletion of GSH, formation of membrane polypeptide aggregates (440,000 and > 50,000,000 daltons) and decreased cell micropipette deformability, abnormalities similar to those observed in the erythrocytes of patients with chronic hemolytic variants of G-6-PD deficiency. In addition, diamide-incubated cells had increased viscosity and increased membrane specific gravity, but no change in ATP. Reinjection of 51Cr-labeled, diamide-incubated cells was followed by markedly shortened in vivo survival and splenic sequestration. Further incubation of diamide-incubated cells in 4 mM dithiothreitol reversed the membrane polypeptide aggregates, normalized micropipette deformability, decreased cell viscosity, prolonged in vivi survival, and decreased splenic sequestration. These studied demonstrate that diamide induces a partially reversible erythrocyte lesion which is a useful model of oxidant-induced membrane injury. They suggest that oxidant-induced erythrocyte membrane injury plays an important role in the pathophysiology of chronic hemolysis which accompanies some G-6-PD variants.
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001391:Azo Compounds / Q000494:pharmacology*; D002470:Cell Survival; D003958:Diamide / Q000494:pharmacology*; D004229:Dithiothreitol / Q000494:pharmacology; D004285:Dogs; D004591:Electrophoresis, Polyacrylamide Gel; D004910:Erythrocyte Membrane / Q000187:drug effects; D004912:Erythrocytes / Q000187:drug effects*; D005978:Glutathione / Q000097:blood; D006366:Heinz Bodies / Q000032:analysis; D008565:Membrane Proteins / Q000032:analysis
chemical_list: D001391:Azo Compounds; D008565:Membrane Proteins; D003958:Diamide; D000255:Adenosine Triphosphate; D005978:Glutathione; D004229:Dithiothreitol