CO-induced K(+) currents in rat glomus cells are insensitive to light unlike carotid body neural discharge and Vo(O(2)).

The hypothesis that the light sensitive properties of CO-induced chemosensory nerve (CSN) discharge and oxygen consumption of the carotid body (CB) were shared by the pre-synaptic glomus cells was tested. The light effect on K(+) currents were measured before and during perfusion of the isolated rat glomus cells with high P(CO) of 550 Torr during nomoxia (P(O(2)approximately equal 100 Torr) at extra-cellular pH 7.0 and intracellular pH 6.8 with HEPES buffer. CO increased the K(+) currents with a left ward shift of the reversal potential, which showed no light effect. Thus the K(+) permeability of the glomus cell membrane were not shared by the light-sensitive CSN discharge of the CB and oxygen consumption in the presence of high P(CO.)