PT  - JOURNAL ARTICLE
AU  - Zachary S. Bowman
AU  - Jason D. Morrow
AU  - David J. Jollow
AU  - David C. McMillan
TI  - Primaquine-Induced Hemolytic Anemia: Role of Membrane Lipid Peroxidation and Cytoskeletal Protein Alterations in the Hemotoxicity of 5-Hydroxyprimaquine
AID  - 10.1124/jpet.105.086488
DP  - 2005 Aug 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 838--845
VI  - 314
IP  - 2
4099  - http://jpet.aspetjournals.org/content/314/2/838.short
4100  - http://jpet.aspetjournals.org/content/314/2/838.full
SO  - J Pharmacol Exp Ther2005 Aug 01; 314
AB  - Primaquine-induced hemolytic anemia is a toxic side effect that is due to premature splenic sequestration of intact erythrocytes. Previous studies have suggested that a phenolic metabolite, 5-hydroxyprimaquine (5-HPQ), mediates primaquine hemotoxicity by generating reactive oxygen species (ROS) within erythrocytes that overwhelm antioxidant defenses. However, the nature of the oxidative stress is not understood, and the molecular targets, whether protein and/or lipid, are unknown. To investigate the mechanism underlying the hemolytic activity of 5-HPQ, we have examined the effect of hemolytic concentrations of 5-HPQ on ROS formation within rat erythrocytes using the cellular ROS probe, 2′,7′-dichlorodihydrofluoresein diacetate. In addition, we examined the effect of 5-HPQ on membrane lipids and cytoskeletal proteins. The data indicate that 5-HPQ causes a prolonged, concentration-dependent generation of ROS within erythrocytes. Interestingly, 5-HPQ-generated ROS was not associated with the onset of lipid peroxidation or an alteration in phosphatidylserine asymmetry. Instead, 5-HPQ induced oxidative injury to the erythrocyte cytoskeleton, as evidenced by changes in the normal electrophoretic pattern of membrane ghost proteins. Immunoblotting with an anti-hemoglobin antibody revealed that these changes were due primarily to the formation of disulfide-linked hemoglobin-skeletal protein adducts. The data suggest that cytoskeletal protein damage, rather than membrane lipid peroxidation or loss of phosphatidylserine asymmetry, underlies the process of removal of erythrocytes exposed to 5-HPQ. The American Society for Pharmacology and Experimental Therapeutics