We measured the respiratory burst activity of adult or cord neutrophils with the
production of H2Oa which changes nonfluorescent DCFH - DA to fluorescent DCF that
is analyzed by flowcytometer. And also the surface expression of neutral
endopeptidase(CALLA/CD10) and aminopeptidase(My7/CD13) was measured with the
binding of phycoerythrin conjugated monoclonal antibody for CALLA/CD10 or My7/CD13
by the surface of neutrophils by flowcytometer.
Cord neutrophils show greater respiratory burst activity than adult neutrophils by
more than twice.
The positivity of surface neutral endopeptidase (CALLA/CD10)and aminopeptidase (My7/CDl3) was
low in cord neutrophils(32% and 72% each) and high in adult
neutrophils(89% and 92% each). And the surface neutral endopeptidase or aminopeptidase
positive neutrophils showed lessrespiratory burst activity than the surface
neutral
endopeptidase or aminopeptidase negative neutrophils In the both of adult neutrophils
and cord netrophils.
The above results are consistent with the hypothesis that the surface peptidases of
neutrophils modulate the respiratory burst activity. We speculate that this Is a part of
control mechanism which limits the intensity of respiratory burst activity of neutrophils.
As matured from cord neutrophils to adult neutrophils the neutrophils are considered to
become to obtain the surface peptidases, one of control mechanism to the response of
neutrophils.

Keywords: Neutrophils, Peptidases, Respiratory Burst