Ascorbate-mediated stimulation of neutrophil motility and lymphocyte transformation by inhibition of the peroxidase/H2O2/halide system in vitro and in vivo.
Neutrophil migration, postphagocytic hexose-monophosphate shunt activity and myeloperoxidase-mediated iodination of ingested Candida albicans and lymphocyte mitogen-induced transformation were assessed in six normal volunteers before and 1 h after a single intravenous injection of 1 g ascorbate. Increased neutrophil motility was observed which was associated with decreased myeloperoxidase-mediated iodination of C. albicans and a slight increase in hexose-monophosphate shunt activity. Lymphocyte transformation was also increased. Alterations in these activities were related to serum ascorbate levels. To investigate the relationship of ascorbate-mediated increased neutrophil motility and lymphocyte transformation to decreased peroxidase activity neutrophils and lymphocytes from normal individuals were exposed to the horseradish peroxidase/H2O2/sodium iodide system in the presence and absence of ascorbate and tested for migratory and proliferative responses respectively. Exposure to the horseradish peroxidase/H2O2/halide system caused inhibition of neutrophil motility and lymphocyte responsiveness to mitogens. However, inclusion of ascorbate protected both the neutrophils and lymphocytes from the inhibitory effects of the horseradish peroxidase/H2O2/halide system.
D001205:Ascorbic Acid / Q000494:pharmacology*; D002634:Chemotaxis, Leukocyte / Q000187:drug effects*; D006735:Horseradish Peroxidase / Q000037:antagonists & inhibitors*; D006801:Humans; D006861:Hydrogen Peroxide / Q000097:blood*; D007454:Iodides / Q000097:blood*; D008213:Lymphocyte Activation / Q000187:drug effects*; D009504:Neutrophils / Q000187:drug effects; D010544:Peroxidases / Q000037:antagonists & inhibitors*; D012974:Sodium Iodide / Q000097:blood*
D007454:Iodides; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase; D010544:Peroxidases; D012974:Sodium Iodide; D001205:Ascorbic Acid