The intracellular chloride activity of glomus cells in the isolated rabbit carotid body.

The resting membrane potential (EM) and intracellular chloride activity (ai(CI] of glomus cells were measured in isolated rabbit carotid bodies using conventional and chloride-selective microelectrodes. EM and ai(CI) were -25.9 +/- 1.4 mV (mean +/- S.E.M., n = 13) and 20.9 +/- 1.9 mV (mean +/- S.E.M., n = 13), respectively. When the chloride equilibrium potential (ECI) was shifted in a positive direction, EM depolarized. It is concluded that chloride ions are not passively distributed across the glomus cell membrane and that they play an important role in determining EM.