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We have examined the induction of hypodense eosinophils by platelet-activating factor (PAF), a mediator which may be involved in eosinophil activation in allergic diseases. Guinea-pig eosinophils were incubated with buffer or PAF and applied to continuous Percoll density gradients. Cellular density ranged from 1.0142 to 1.1369 g/ml. Peak eosinophil density in control was 1.0887 +/- 0.0008 g/ml (mean +/- SEM), and 91.1 +/- 1.4% of eosinophils were distributed between 1.0810 and 1.1000 g/ml. Preincubation of eosinophils with PAF(10(-7) M) resulted in a time-dependent and non-cytolytic increase of the number of hypodense eosinophils, with peak densities after incubation for 1 hr and 2 hr of 1.0834 +/- 0.0014 (n = 4, P less than 0.05) and 1.0755 +/- 0.0007 g/ml (n = 6, P less than 0.01), respectively. After incubation for 2 hr, 82.0 +/- 4.9% (n = 6) eosinophils showed a density lower than 1.080 g/ml. Lyso-PAF, the inactive precursor and metabolite of PAF, at a concentration of 10(-7) M had no effect on cell density. The specific PAF receptor antagonist WEB 2086 (10(-6) M) inhibited the PAF-induced density shift by 87.0 +/- 5.3%. Our results demonstrate that a single mediator is able to induce the formation of hypodense eosinophils. We conclude that the appearance of hypodense eosinophils in allergic diseases such as asthma may occur, at least in part, in response to inflammatory mediators which activate these cells.
T Yukawa, and
C Kroegel, and
P Evans, and
T Fukuda, and
K F Chung, and
P J Barnes
December 1991,
Lipids,
T Yukawa, and
C Kroegel, and
P Evans, and
T Fukuda, and
K F Chung, and
P J Barnes
August 1991,
The Journal of allergy and clinical immunology,
T Yukawa, and
C Kroegel, and
P Evans, and
T Fukuda, and
K F Chung, and
P J Barnes
December 1990,
Journal of immunology (Baltimore, Md. : 1950),
T Yukawa, and
C Kroegel, and
P Evans, and
T Fukuda, and
K F Chung, and
P J Barnes
January 1994,
International archives of allergy and immunology,
T Yukawa, and
C Kroegel, and
P Evans, and
T Fukuda, and
K F Chung, and
P J Barnes
October 1996,
Clinical and experimental immunology,
T Yukawa, and
C Kroegel, and
P Evans, and
T Fukuda, and
K F Chung, and
P J Barnes
September 1992,
Respiratory medicine,
T Yukawa, and
C Kroegel, and
P Evans, and
T Fukuda, and
K F Chung, and
P J Barnes
August 1987,
Prostaglandins,
T Yukawa, and
C Kroegel, and
P Evans, and
T Fukuda, and
K F Chung, and
P J Barnes
March 1996,
Proceedings of the National Academy of Sciences of the United States of America,
T Yukawa, and
C Kroegel, and
P Evans, and
T Fukuda, and
K F Chung, and
P J Barnes
January 1992,
American journal of respiratory cell and molecular biology,
T Yukawa, and
C Kroegel, and
P Evans, and
T Fukuda, and
K F Chung, and
P J Barnes
January 1989,
Allergy proceedings : the official journal of regional and state allergy societies,
