The locomotive forces produced by single leukocytes in vivo and in vitro. Gore, William H. Guilford R. Clark Lantz & Robert W. Departments of Physiology and Anatomy, College of Medicine, University of Arizona, Tucson, Arizona, 85724., Phone: (602) 626 - 6569, Fax: (602) 626 - 2382
APStracts 2:0091C, 1995.
We report here the first time-resolved measurements of the forces produced during the migration of single leukocytes in vivo and in vitro. Pulmonary macrophages from hamsters and mice in vitro, and Nembutol-anesthetized hamster neutrophils in vivo, generated maximum locomotive forces ranging from 1.9 to 10.7 nanonewtons, or tenths of dynes. Force production was periodic, and correlated with the length of the leading lamellipod, but not with generalized cell ruffling. Although the extension of the leading lamella is critical to locomotive force generation, these direct measurements suggest that lamellar extension may not arise from the same contractile processes driving forward motion of the cell mass. Indeed, cell ruffling, lamellar extension and locomotive force generation may be differentially controlled and have different origins. This technique may be extended to test numerous hypotheses of how these and other non-muscle cells crawl.

Received 3 October 1994; accepted in final form 20 January 1995.
APS Manuscript Number C594-4.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 28 February 1995.