Affiliations: Department of Physiology, Division of Medical Science, The Medical School, The University of Birmingham, Birmingham B15 2TT, UK
Note: [] Address for correspondence: Prof. G.B. Nash, Department of Physiology, The Medical School, The University of Birmingham, Birmingham B15 2TT, UK. Tel: +44 (0)121 414 3670; Fax: +44 (0)121 414 6919; E‐mail: g.nash@bham.ac.uk.
Abstract: Increase in the resistance to deformation of neutrophils upon exposure to the cold may impair their passage through microvessels. However, the potential for such rheological changes to cause prolonged microvascular obstruction in cooled tissue will depend on whether and at what rate the neutrophils recover on rewarming. We tested the ability of neutrophils to pass through micropore filters, and found that neutrophils cooled to 10°C for 10–20 minutes could block either 5 μm or 8 μm pore filters. On return to 37°C, flow resistance remained impaired briefly but recovered over about 5 minutes. The kinetics of changes in flow resistance in the cold and on rewarming were linked to kinetics of actin polymerisation during these periods. However, they were not closely linked to distortion of cell shape in the cold, which recovered only slowly with rewarming. The results suggest that while rigid neutrophils might occlude capillaries in cold tissue, mechanical obstruction should not be long‐lived on rewarming. Moreover, rigid neutrophils washed out of cold tissue should experience only temporary mechanical trapping in remote tissues.
