Expression of at1a and at1b angiotensin ii receptor messenger rna
in forebrain of two-week-old rats.
J[diaeresis]ohren, Olaf, and Juan M. Saavedra.
Section on Pharmacology, Laboratory of Clinical Science, National
Institute of Mental Health, Bethesda, MD 20892
APStracts 3:0058E, 1996.
The gene expression of AT1A and AT1B angiotensin II receptors was
localized in the forebrain of two-week-old rats by in situ
hybridization histochemistry and compared with [125I]Sar1-angiotensin
II binding patterns. AT1A receptor mRNA was expressed in
circumventricular organs, in hypothalamic nuclei like the
paraventricular nucleus, in the lateral olfactory tract, in the
basolateral amygdaloid and anterior olfactory nuclei, and in the
piriform cortex. No AT1B receptor mRNA was detected in these areas.
AT1A and AT1B receptor mRNA was detected in the hippocampus,
cingulate cortex, and choroid plexus. No forebrain area studied
expressed AT1B receptor mRNA exclusively. Mostly, a good match for
receptor mRNA and binding was found. In some areas, apparent
mismatches suggested receptor formation elsewhere (median eminence),
or receptor presence in local neuronal circuits (hippocampus,
cingulate and piriform cortex). Our results support the hypothesis
that AT1A receptors are involved in the classical central functions
of angiotensin II. Both AT1A and AT1B receptors may play roles in
cortical and limbic system function, particularly early in
development.
Received 13 October 1995; accepted in final form 27 February
1996.
APS Manuscript Number E497-5.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 20 March 96