RT info:eu-repo/semantics/article
T1 Localization and Function of Cat Carotid Body Nicotinic Receptors
A1 Dinger, Bruce
A1 González, Constancio
A1 Yoshizaki, Katsuaki
A1 Fidone, Salvatore
K1 Neurofisiología
AB Acetylcholine and nicotinic agents excite cat carotid body chemoreceptors and modify their response to natural stimuli. The presentexperiments utilized [125I]a-bungarotoxin ([125I]a-BGT) to localize within the chemosensory tissue the possible sites of action of exogenousand endogenous nicotinic cholinergic substances. In vitro equilibrium binding studies of intact carotid bodies determined a K d of5.57 nM and a Bma x of 9.21 pmol/g of tissue. Chronic section (12-15 days) of the carotid sinus nerve (CSN) did not change the amountof displaceable toxin binding. In contrast, the specific binding was reduced by 46% following removal of the superior cervical ganglion.Light microscope autoradiography of normal, CSN-denervated and sympathectomized carotid bodies revealed displaceable bindingsites concentrated in lobules of type I and type II cells. Treatment of carotid bodies with 50 nM a-BGT in vitro reduced by 50% therelease of [3H]dopamine (synthesized from [3H]tyrosine) caused by hypoxia or nicotine, and also significantly reduced the stimulus-.evoked discharges recorded from the CSN. The data suggest (1) an absence of ct-BGT binding sites on the afferent terminals of theCSN and (2) that nicotinic receptors located within parenchymal cell lobules may modulate the release of catecholamines from these cells.
PB Elsevier
SN 0006-8993
YR 1985
FD 1985
LK http://uvadoc.uva.es/handle/10324/6845
UL http://uvadoc.uva.es/handle/10324/6845
LA eng
NO Brain Research, 1985, vol. 339, p. 295-304
NO Producción Científica
DS UVaDOC
RD 18-dic-2024