Gadolinium inhibits mechanoelectrical transduction in rabbit carotid baroreceptors. Implication of stretch-activated channels.
Gadolinium (Gd3+) has been shown to prevent mechanoelectrical transduction believed to be mediated through stretch-activated channels. We investigated the possible role of Gd(3+)-sensitive channels in mediating baroreceptor activity in the carotid sinus of rabbits. Baroreceptor activity induced by a ramp increase of carotid sinus pressure was reduced significantly during exposure to Gd3+. The inhibition was dose-related and reversible, and was not associated with alteration of carotid sinus wall mechanics as the pressure-strain relationship was unaffected. Veratrine triggered action potentials from single- and multiple-baroreceptor fibers when their response to pressure was inhibited by Gd3+. This suggests that the effect of Gd3+ on baroreceptors in the isolated carotid sinus was specific to their mechanical activation. The results suggest that stretch-activated ion channels sensitive to Gd3+ may be the mechanoelectrical transducers of rabbit carotid sinus baroreceptors.
Hajduczok
G
G
Cardiovascular Center, University of Iowa College of Medicine, Iowa City 52242.
Chapleau
M W
MW
Ferlic
R J
RJ
Mao
H Z
HZ
Abboud
F M
FM
D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D002346:Carotid Sinus / Q000502:physiology*; D004558:Electric Stimulation; D005260:Female; D005682:Gadolinium / Q000494:pharmacology*; D007473:Ion Channels / Q000187:drug effects / Q000502:physiology*; D008297:Male; D010812:Physical Stimulation; D011311:Pressoreceptors / Q000187:drug effects / Q000502:physiology*; D011817:Rabbits; D015398:Signal Transduction / Q000187:drug effects*; D014702:Veratrine / Q000494:pharmacology
D007473:Ion Channels; D005682:Gadolinium; D014702:Veratrine