PMN heterogeneity: long-term stability of fluorescent membrane potential
responses to the chemoattractant N-formyl-methionyl-leucyl- phenylalanine
in healthy adults and correlation with respiratory burst activity
MP Fletcher and BE Seligmann
Polymorphonuclear neutrophils (PMNs) were isolated from 24 healthy adults
20 to 61 years of age and the proportion of cells that demonstrated
depolarization responses to the synthetic chemotaxin N-
formyl-methionyl-leucyl-phenylalanine (FMLP) were enumerated using the
lipophilic fluorescent cyanine dye 3,3'-di-pentyl-oxacarbocyanine [di-O-
C(5)(3)] and flow cytometry. The membrane potential responses were
correlated to the cells' respiratory burst capabilities as measured by
nitroblue tetrazolium (NBT) reduction and/or superoxide production in
response to FMLP; 40.2% +/- 15.1% (mean +/- SD) of cells depolarized to
FMLP. The mean SE for duplicate determinations 1 hour apart was 3.8% (range
0.4% to 13.6%, n = 15). There was no correlation between the percentage of
depolarizing PMNs and the yield of cells, the percentage of immature cells,
or the circulating WBC count. There was no difference in the average age of
men (34.9 +/- 9.9 years, n = 11) v women (33.8 +/- 8.5, n = 13) (mean +/-
SD) studied, or in the percentage of depolarizing PMNs when men and women
were compared (42.2 +/- 10.6% v 43.1 +/- 13.3%, respectively). However,
there was a significant increase in the percentage of depolarizing PMNs
with increasing age of women (r = .61, P less than .025) but not men (r =
.03, P greater than .05). Analysis of variance revealed significantly
greater person-to-person variability in the membrane potential response
than in day-to-day variability in the same person (P less than .0005). The
percentage of depolarizing PMNs in response to FMLP was significantly
correlated with the percentage of NBT-positive cells from both purified
PMNs and from whole blood (r = .849, P less than .0005, r = .857, P less
than .05, respectively), and with the amount of superoxide produced,
expressed as a percentage of that amount produced by cytochalasin B
(cyto-B)-pretreated cells (r = .565, P less than .01). The data indicate
that PMNs from healthy adults demonstrate a heterogeneous membrane
potential response to the chemotaxin FMLP that correlates with the cells'
oxidative responsiveness and that intersubject differences can be detected.
In addition, the proportion of responsive PMNs increases with increasing
age in women.
Volume 68,
Issue 3,
pp. 611-618,
09/01/1986
Copyright © 1986 by The American Society of Hematology
