2026-05-18T21:17:14Zhttps://uvadoc.uva.es/oai/requestoai:uvadoc.uva.es:10324/68212025-03-03T10:32:32Zcom_10324_32522com_10324_952com_10324_894com_10324_43677com_10324_954com_10324_1134com_10324_931col_10324_32523col_10324_43678col_10324_1213
UVaDOC
author
López López, José Ramón
author
González Martínez, Constancio
2014-10-30T08:50:46Z
2014-10-30T08:50:46Z
1992
FEBS Letters, 1992, vol. 299, n. 3. p. 251-254
0014-5793
http://uvadoc.uva.es/handle/10324/6821
10.1016/0014-5793(92)80126-2
251
3
254
FEBS Letters
299
Carotid body (CB) chemoreceptors respond to a decrease
in arterial blood pOz with an increase in action
potential frequency in the sensory fibers innervating the
organ, the response developing in a few seconds [l].
Chemoreceptor cells of the CB are the Oz sensing structures,
releasing neurotransmitters in proportion to the
pOz decrease and producing an electrical discharge of
parallel intensity in the sensory nerve fibers of the carotid
sinus nerve [2,3]. Recently, it has been shown that
chemoreceptor cells possess an O,-sensitive K’ current
that is reversibly inhibited by decreasing pOz in the
bathing solution. The suggestion was made that this
inhibition can lead to cell depolarization and activation
of voltage-dependent Ca” channels [4,5]; the entry of
Ca”+ through these channels, that are dihydropyridinesensitive,
would trigger the release of neurotransmitters
[6,7]. To accept this sequence, the inhibition of the K’
current must precede the activation of the sensory nerve
discharges [8], that is, the inhibition mus: develop
within the initial 3 s after lowering pOz, the time elapsing
between a decrease in arterial pO1! and the increase
in the carotid sinus nerve action potential frequency [l].
On the other hand, the suggestion has been made that
the O?-sensor in chemoreceptor cells should be a hemoglobin-
like hemoprotein, but no direct evidence to
support this suggestion is available [l]. The presentstudy compares the time course of the inhibition of the
K’ current by low pO1 and that of Na” current inhibition
by TTX, which is known to occur in a few hundred
ms [SJ. I: is shown that the former inhibition is faster.
It is also shown that carbon monoxide, a very inert gas
that in biological systems only reacts with hemoproteins,
prevents the low PO,-induced inhibition of
chemorcceptor cells E;” current.
eng
Células - Receptores
Cuerpo carotídeo
Cells - Receptors
Carotic body
Time course of K+ current inhibition by low oxygen in chemoreceptor cells of adult rabbit carotid body. Effects of carbon monoxide
info:eu-repo/semantics/article