Regulation of neutrophil superoxide generation by alpha-tocopherol in human peripheral and umbilical-cord blood.
OBJECTIVE
Alfa-tocopherol (VE) inhibits protein phosphorylation and affects protein kinase C (PKC)-dependent superoxide (O2) generation of phagocytic cells. Because umbilical-cord blood contains low concentrations of VE, we studied the effects of VE on stimulation-dependent O2 generation of neutrophils derived from the healthy human peripheral circulation (HPMNs) and the umbilical cord (UCBNs).


METHODS
O2- generation and VE content were assayed by reduction of ferricytochrome c and by HPLC with an electrochemical detector, respectively. Neutrophil-specific annexin protein was identified by an immunological method.


RESULTS
Both types of neutrophils generate significant amounts of PKC-dependent O2-generation, but weak PKC-independent O2-generation, except for opsonized zymosan-stimulated O2- generation in UCBNs. The VE content of UCBNs was similar to that of HPMNs although umbilical-cord blood contains a low concentration of VE. A neutrophil-specific annexin protein was also found in the UCBNs.


CONCLUSIONS
UCBNs have a greater ability to incorporate VE than HPMNs do, but have similar general characteristics of stimulation-dependent O2-generation to those of HPMNs.
Ando
M
M
Department of Obstetrics and Gynecology, Okayama University Medical School, Japan.
Yoshioka
T
T
Akiyama
J
J
Kudo
T
T
D017305:Annexin A1 / Q000032:analysis; D000001:Calcimycin / Q000494:pharmacology; D005312:Fetal Blood / Q000166:cytology*; D006801:Humans; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects* / Q000378:metabolism*; D011493:Protein Kinase C / Q000097:blood; D013481:Superoxides / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014810:Vitamin E / Q000097:blood / Q000494:pharmacology*
D017305:Annexin A1; D013481:Superoxides; D014810:Vitamin E; D000001:Calcimycin; D009240:N-Formylmethionine Leucyl-Phenylalanine; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate