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LUIS A. OLIVOS-ORÉ Y COLS. AN. R. ACAD. NAC. FARM.

empeñarían un papel modulador comportamiento eléctrico de dichas
células.

Palabras clave: Receptor nicotínico; célula cromafín; potencial de
membrana; canales SK.

ABSTRACT

Pharmacological characterization and functional analysis of
a9a10 acetylcholine nicotinic receptors in isolated chromaffin
cells from the rat adrenal medulla

The identification of acetylcholine nicotinic receptors (nAChRs)
formed by a9 and a10 subunits in the sensory cells of the vestibular
and auditory systems, prompted us to investigate their presence in
adrenomedullary chromaffin cells, in which they could mediate mem-
brane hyperpolarization through the activation of small-conductance
Ca2+-dependent K+ channels (SK channels). The aim of the current
study has been to pharmacologically identify a9a10 nAChRs and in-
itiate their functional characterization in isolated chromaffin cells
from the rat adrenal medulla. We have employed the patch clamp
technique to record either the ionic currents generated by the activa-
tion of nAChRs or the associated changes in membrane potential. We
took advantage of the specificity of a-conotoxin RgIA for the nAChRs
formed by a9 and a10 subunits. Our pharmacological results suggest
that the rat chromaffin cells express functional a9a10 nAChRs that
would influence the electrical behaviour of these cells.

Keywords: Acetylcholine nicotinic receptor; chromaffin cell; mem-
brane potencial; SK channels.

1. INTRODUCCIÓN

Los receptores colinérgicos nicotínicos (nAChRs) son canales ió-
nicos activados por ligando —el ligando endógeno es la acetilcoli-
na— formados por la asociación de cinco subunidades con pesos
moleculares comprendidos entre 40 y 58 kDa. En la actualidad se

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