Locomotion forces generated by a polymorphonuclear leukocyte.
There have been very few studies which have measured the physical forces generated by cells during active movements. A special micropipette system has been designed to make it possible to observe cell motion within the pipette and to apply a pressure to counter the chemotactic migration of the cell. This provides a direct measure of the locomotion force generated by the cell. The average velocity of forward motion is 0.33 microns/s in the absence of counter-pressure. The application of a positive counter-pressure (C-P) causes a decrease in the velocity of the forward motion of the cell. At 17 cm H2O of C-P, the cell velocity drops to zero and even moves backward with a higher C-P. The results show that the decrement of velocity is linearly related to the magnitude of the C-P with a complete stoppage at a pressure of 17 cm H2O which corresponds to a force of 0.003 dyn. The maximum work rate of the cell is approximately 2.5 x 10(-8) erg/s.
Usami
S
S
Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, ROC.
Wung
S L
SL
Skierczynski
B A
BA
Skalak
R
R
Chien
S
S
D001696:Biomechanical Phenomena; D055592:Biophysical Phenomena; D001703:Biophysics; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology; D002634:Chemotaxis, Leukocyte / Q000187:drug effects / Q000502:physiology; D006801:Humans; D066298:In Vitro Techniques; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects / Q000502:physiology*
D009240:N-Formylmethionine Leucyl-Phenylalanine