Details

Autor(en) / Beteiligte

• Rochon, Yvan P.
• Frojmovic, Mony M.

Titel

Dynamics of human neutrophil aggregation evaluated by flow cytometry

Ist Teil von

• Journal of leukocyte biology, 1991-11, Vol.50 (5), p.434-443

Ort / Verlag

Bethesda, MD: Society for Leukocyte Biology

Erscheinungsjahr

1991

Quelle

MEDLINE

Beschreibungen/Notizen

• In order to directly monitor neutrophil aggregation, we have developed a simple particle counting technique using flow cytometry. Flow times were used to determine aggregation from changes in the total number of particles per unit volume (%PAT), while fluorescent signals emitted from glutaraldehyde‐fixed neutrophils were used to measure changes in the total number of singlet neutrophils (%PAgs). Flow cytometrically‐determined %PA values were found to be virtually identical to values determined from microscopy. We show that aggregation parameters can be evaluated and compared simply from measures of changes in total particle count without a need for distinguishing singlets from murtiplets. A number of aggregation parameters are introduced and related to the initial cell concentration (No) and stir speed (shear). Aggregation of neutrophils, following stimulation with 0.5 μM FMLP (N‐formyl‐methionyl‐leucyl‐phenylalanine), showed a latent time (ti) of 4 ± 1.5 sec independent of No or stir speed; had a forward rate of aggregation (v,) which was proportional to the initial cell concentration and the stir speed; plateaued for ≥ 60 s; and showed partial to complete reversal by 7.5 min. Above a critical stir speed, the extent and duration of aggregation varied inversely with the stir speed. The stir and No dependence of the aggregation parameters studied suggest the existence of subpopulations of neutrophils with distinct efficiencies of aggregation.