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An Investigation of Noradrenaline Uptake and Release by the CATH.a Cell Line
Author(s) -
Bundey Richard A.,
Jones Philip G.,
Kendall David A.
Publication year - 2000
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1046/j.1471-4159.2000.740799.x
Subject(s) - locus coeruleus , endogeny , cell culture , neurotransmitter , norepinephrine , norepinephrine transporter , transporter , cell , chemistry , in vitro , microbiology and biotechnology , biology , medicine , endocrinology , biophysics , nucleus , biochemistry , gene , central nervous system , dopamine , genetics
The cell bodies of ascending noradrenergic neurons in the brain are located predominantly in the locus coeruleus. An in vitro model of locus coeruleus neurons could prove to be a useful tool in the investigation of noradrenergic neural networks and their associated pathophysiologies. The CATH.a cell line demonstrates some of the properties expected of locus coeruleus neurons, and the present study investigated the neurotransmitter uptake and release properties of the CATH.a cells. It was surprising that the CATH.a cells failed to accumulate [ 3 H]noradrenaline ([ 3 H]NA), suggesting the lack of a functional NA transporter. RT‐PCR supported this finding by demonstrating the absence of NA transporter mRNA. Treatment of CATH.a cells with various differentiating agents failed to increase the [ 3 H]NA uptake. Endogenous NA release was studied using HPLC detection, which revealed a lack of depolarisation‐induced increases in endogenous NA release. A human NA transporter‐transfected CATH.a cell line was generated (termed RUNT), and a study of the [ 3 H]NA uptake revealed that the RUNT cells displayed significant uptake that could be blocked by cocaine (10 μ M ). Furthermore, the uptake capacity could be dramatically increased by differentiation of the cells with dibutyryl cyclic AMP (1 m M ) for 24 h. Using dibutyryl cyclic AMP‐differentiated RUNT cells, high K + concentrations (50 m M ) significantly increased [ 3 H]NA release above basal levels.