AJP - Cell Physiology, Vol 233, Issue 1 35-C46, Copyright © 1977 by American Physiological Society
Effects of temperature on some membrane characteristics of carotid body cells
M. Baron and C. Eyzaguirre
Excised cat carotid bodies and nerves were placed in a Lucite chamber
through which saline flowed at different temperatures. Action potentials
were recorded with a suction electrode. Glomus cells were impaled with
microelectrodes and identified by ejecting Procion navy blue from the
micropipette. Membrane potentials (MP) averaged 20 mV and input resistances
(R0), 40 Momega. Cooling induced depolarization and decreased R0. This
effect had a reversal potential of about -6 mV. [K+]0 did not affect MP,
R0, or cooling effects. Lack of sodium increased MP, R0, and depressed
cooling effects. Low chloride had opposite effects. Ca2+ and Mg2+
influenced MP and R0 but had little effects on temperature actions. Ouabain
decreased MP and R0. Results indicate that glomus cells are exquisitely
sensitive to temperature changes; their MP and R0 increase with high
temperatures and decrease when temperature is lowered. These effects are
mostly dependent on the external concentration of Cl- and Na+. Glomus cells
may be the site of the intense metabolism of this tissue and thus
contribute to the generation of chemosensory impulses.
