title: Quenching of singlet oxygen by D-alpha-tocopherol in human granulocytes.
abstract: The ability of D-alpha-tocopherol to act as a quencher of (1)0(2) (singlet oxygen) was tested with a biological source of (1)0(2), namely the phagocytosis activated myeloperoxidase contained in the homogenate of human circulating polymorphonuclear leukocytes. With this system, the (1)0(2) quenching efficiency of exogenously added D-alpha-tocopherol was estimated from its inhibitory effect on the luminol amplified chemiluminescence. This inhibitory effect was dose dependent. D-alpha-tocopherol was also efficient in quenching the chemiluminescence generated through the H2O2-horseradish system. In both systems the quenching effect may be almost entirely "physical", since very little tocopherol was destroyed when compared to the relatively large amount of H2O2 consumed.
mesh_terms: D006801:Humans; D006861:Hydrogen Peroxide / Q000097:blood; D007700:Kinetics; D008163:Luminescent Measurements; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D010100:Oxygen / Q000097:blood*; D010587:Phagocytosis; D010777:Photochemistry; D026082:Singlet Oxygen; D014810:Vitamin E / Q000494:pharmacology*
chemical_list: D014810:Vitamin E; D026082:Singlet Oxygen; D006861:Hydrogen Peroxide; D010100:Oxygen