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Mechanical deformation decreases activation time for neutrophils
Author(s) -
Burdette Aaron Jeffrey,
Rogers Steven,
Tees David F.J.
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.859.8
Subject(s) - pipette , deformation (meteorology) , biophysics , calcium , pseudopodia , chemistry , calcium in biology , materials science , composite material , cell , biology , biochemistry , organic chemistry
Activation of polymorphonuclear leukocytes (PMN) can be induced by mechanical deformation. When a PMN is aspirated into a micropipette of a smaller diameter than of the cell, the cell experiences mechanical deformation. Activation is assumed to occur when pseudopod projection is observed, along with an influx of intracellular calcium. We hypothesize that increased deformation of PMNs leads to faster activation. The size of micropipettes (~5–7 μm) used mimicked the conditions inside lung capillaries. We measured the elapsed time required for activation following aspiration into various pipette diameters. The cell‐penetrating calcium‐sensitive dye Fura‐2AM was loaded on to the PMN to detect increases in the intracellular calcium. The ratios of intensity among the two excitation wavelengths, 340 nm and 380 nm, give calcium concentration. A cooled intensified CCD camera was used to measure the intensities every 15 s. From observations of pseudopod projection, the activation time of the PMN was inversely proportional to the amount of mechanical deformation as characterized by the deformation ratio of cell diameter to the diameter of the micropipette. This supported our hypothesis that increased deformation would decrease activation time. This work was supported by grant BES‐0547165 from the National Science Foundation.