AJP - Cell Physiology, Vol 256, Issue 3 C644-C651, Copyright © 1989 by American Physiological Society
Density-dependent hyperpolarization in cultured aortic smooth muscle cells
M. G. Blennerhassett, M. S. Kannan and R. E. Garfield
Department of Neurosciences, Faculty of Health Sciences, McMaster University, Hamilton, Ontario, Canada.
The membrane potential (Em) of cultured aortic smooth muscle cells from
Sprague-Dawley (SD), Wistar-Kyoto (WKY), and spontaneously hypertensive
(SHR) rats was measured in proliferating primary cultures. Em of SD cells
in high-density cultures was -51 to -58 mV, whereas that of low-density
cultures (1-2 days) was -30 mV. This difference was due to a continuous
process of hyperpolarization during proliferation in culture. Em of WKY and
SHR hyperpolarized similarly, from -12 to -42 and -38 mV, respectively.
Hyperpolarization of Em of SD, WKY, and SHR cells was related to cell
density rather than time in culture. Em may be a sensitive and significant
indicator of the changes in the differentiated state expressed by
proliferating smooth muscle in vitro.
