Vol. 275, Issue 1, R234-R244, July 1998
Central angiotensin AT1 and
muscarinic receptors in ITF expression on intracerebroventricular
NaCl
E.
Moellenhoff,
C. J.
Lebrun,
A.
Blume,
J.
Culman,
T.
Herdegen, and
T.
Unger
Institute of Pharmacology, University of Kiel, 24105 Kiel; and
German Institute for High Blood Pressure Research, 69120 Heidelberg, Germany
In the present study, we investigated the
expression pattern of the inducible transcription factors (ITF) c-Fos,
c-Jun, JunB, JunD, and Krox-24 following intracerebroventricular
injections of hyperosmolar saline (0.2, 0.3, and 0.6 M NaCl) and its
mediation via angiotensin and/or muscarinic receptors. c-Fos,
c-Jun, and Krox-24 were differentially expressed in organum vasculosum
laminae terminalis, median preoptic area, subfornical organ (SFO), and paraventricular and supraoptic nuclei. Expression of c-Fos and c-Jun
was inhibited by pretreatment with the angiotensin
AT1 receptor antagonist losartan
(10 and 20 nmol icv) following 0.20 and 0.30 M saline. Pretreatment
with atropine (15 nmol icv) inhibited the 0.30 and 0.60 M NaCl-induced
expression of c-Fos, c-Jun, and Krox-24 in all areas except the SFO.
Coexpression of the ITF with vasopressin and oxytocin, the major
effector peptides in osmoregulation, was demonstrated, implying the
corresponding genes as putative target genes of the ITF. The results
show a highly differentiated ITF expression pattern in the brain
mediated by angiotensinergic and muscarinergic pathways, suggesting a
finely tuned regulation of target genes.
central osmoregulation; c-Fos; c-Jun; Krox-24; losartan; atropine
