Oxidative hemolysis of erythrocytes and its inhibition by free radical scavengers.
The oxidative hemolysis of rabbit erythrocytes induced by free radicals and its inhibition by chain-breaking antioxidants have been studied. The free radicals were generated from either a water-soluble or a lipid-soluble azo compound which, upon its thermal decomposition, gave carbon radicals that reacted with oxygen immediately to give peroxyl radicals. The radicals generated in the aqueous phase from a water-soluble azo compound induced hemolysis in air, but little hemolysis was observed in the absence of oxygen. Water-soluble chain-breaking antioxidants, such as ascorbic acid, uric acid, and water-soluble chromanol, suppressed the hemolysis dose dependently. Vitamin E in the erythrocyte membranes was also effective in suppressing the hemolysis. 2,2,5,7,8-Pentamethyl-6-chromanol, a vitamin E analogue without phytyl side chain, incorporated into dimyristoylphosphatidylcholine liposomes, suppressed the above hemolysis, but alpha-tocopherol did not suppress the hemolysis. Soybean phosphatidylcholine liposomes also induced hemolysis, and a lipid-soluble azo initiator incorporated into the soybean phosphatidylcholine liposomes accelerated the hemolysis. The chain-breaking antioxidants incorporated into the liposomes were also effective in suppressing this hemolysis.
Niki
E
E
Department of Reaction Chemistry, Faculty of Engineering, University of Tokyo, Japan.
Komuro
E
E
Takahashi
M
M
Urano
S
S
Ito
E
E
Terao
K
K
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology; D004912:Erythrocytes / Q000187:drug effects / Q000648:ultrastructure; D005609:Free Radicals; D006461:Hemolysis / Q000187:drug effects; D066298:In Vitro Techniques; D008081:Liposomes; D010084:Oxidation-Reduction; D010713:Phosphatidylcholines; D011817:Rabbits; D012016:Reference Values; D014811:Vitamin E Deficiency / Q000097:blood
D000975:Antioxidants; D005609:Free Radicals; D008081:Liposomes; D010713:Phosphatidylcholines; D001205:Ascorbic Acid