AJP - Cell Physiology, Vol 232, Issue 3 138-C143, Copyright © 1977 by American Physiological Society
Detection of contraction of isolated smooth muscle cells in suspension
J. J. Singer and F. S. Fay
A Coulter counter has been utilized to assess the contractile state of
suspensions of isolated smooth muscle cells prepared by enzymatic digestion
of stomach muscularis of Bufo marinus. Pulse-duration and pulse-hieght
histograms were constructed from the pulses that occur as cells pass
through the Coulter counter orifice. Contraction of cells in suspension
causes shifts in these pulse histograms to a greater percent of shorter
duration pulses and of larger pulse heights. These shifts are consistent
with teh assumption made in out studies that the duration and amplitude of
the pulses generated are related to the length and cross-sectional area (or
square of the diameter), respectively, of the cell. Shifts in the
pulse-height histogram were found to be more reliable. The results of a
calibration experiment in which shifts in the histograms of pulse heights
were linerrly related to shifts in the histograms of all lengths measured
from photomicrographs suggested that the shifts in the pulse-height
histogram could be used as a continuous index of changes in the contractile
state of a population of cells in suspension.
