A. Roy et al., Reduced glutathione, dithiothreitol and cytochrome P-450 inhibitors do notinfluence hypoxic chemosensory responses in the rat carotid body, BRAIN RES, 889(1-2), 2001, pp. 131-137
Glomus cells and carotid sinus afferents are anatomically connected, and th
e chemical events in the glomus cells are expected to be conveyed reflexly
as afferent signals. Accordingly, K+ channel inhibition of the glomus cell
membrane is expected to be followed by excitation of the afferents. In orde
r to test the redox inhibition of K+ channels of glomus cells by reduced gl
utathione (GSH), dithiothreitol (DTT) and by cytochrome P-450 inhibitors (c
lotrimazole and miconazole), we measured the carotid sinus nerve (CSN) disc
harge using an in vitro perfused adult rat carotid body (CB) in the presenc
e and absence of these chemicals which are expected to excite the afferents
. Our findings were that these agents did not stimulate the CSN activities
during normoxia and kept the hypoxic responses intact. These results led us
to conclude that the redox modulation of glomus cells was not conveyed to
the afferents, and this functional disconnection did not support the redox
hypothesis of O-2 chemorecrption in the whole carotid body. (C) 2001 Elsevi
er Science B.V. All rights reserved.