P. Zanassi et al., Pharmacological and molecular evidence for dopamine D-1 receptor expression by striatal astrocytes in culture, J NEUROSC R, 58(4), 1999, pp. 544-552
The neurotransmitter dopamine (DA) at a 10 mu M concentration elicited a st
imulation of intracellular cyclic AMP (cAMP) accumulation in cultured astro
cytes derived from embryonic rat striatum. This accumulation was partially
blocked by the beta-adrenergic receptors antagonist propranolol, mimicked b
y the D-1 agonist SKF 38393 and by the mixed D-1/D-2 agonist apomorphine. A
regional heterogeneity in the magnitude of dopamine-induced cAMP accumulat
ion was observed in cultured astrocytes obtained from different brain areas
. The maximum effect was observed in striatal astrocytes, a lower effect in
cortical astrocytes, and no increase was detected in cerebellar astrocytes
, Reverse transcription-polymerase chain reaction (RT-PCR) coupled to South
ern blot hybridization demonstrated that striatal astrocytes express only D
-1 receptor mRNA and Western blot analysis confirmed the expression of the
D-1 receptor protein in striatal astrocytes, In contrast to what found in n
eurons, the D-1-dependent cAMP formation ia striatal astrocytes is partiall
y reduced by pertussis toxin (PTX) treatment, The stimulation of D-1 recept
ors or the activation of adenylyl cyclase by forskolin led to an increase o
f cytosolic and nuclear protein kinase A (PKA) catalytic activity. The pres
ence of dopamine D-1 receptors in cultured striatal astrocytes suggests a r
ole of dopamine in the regulation of cellular processes in striatal astrocy
tes. J. Neurosci. Res. 58:544-552, 1999. (C) 1999 Wiley-Liss, Inc.