LOCALIZATION OF AT(2) ANGIOTENSIN-II RECEPTOR GENE-EXPRESSION IN RAT-BRAIN BY IN-SITU HYBRIDIZATION HISTOCHEMISTRY

Citation
O. Johren et al., LOCALIZATION OF AT(2) ANGIOTENSIN-II RECEPTOR GENE-EXPRESSION IN RAT-BRAIN BY IN-SITU HYBRIDIZATION HISTOCHEMISTRY, Molecular brain research, 37(1-2), 1996, pp. 192-200
Citations number
30
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Neurosciences
Journal title
ISSN journal
0169-328X
Volume
37
Issue
1-2
Year of publication
1996
Pages
192 - 200
Database
ISI
SICI code
0169-328X(1996)37:1-2<192:LOAARG>2.0.ZU;2-M
Abstract
To localize the gene expression of AT(2) angiotensin II receptors in r at brain we performed in situ hybridization histochemistry using S-35- labeled antisense riboprobes. The AT(2) receptor mRNA expression patte rn was compared in consecutive brain sections, from 2 week old rats, w ith the receptor expression by means of [I-125]Sar(1)-ANG II binding a nd displacement with AT(2) selective ligands followed by autoradiograp hy. Expression of AT(2) receptor mRNA was found in several thalamic nu clei (ventral posterolateral, mediodorsal, central medial, paracentral , and paraventricular), the medial geniculate nuclei, the nucleus of t he optic tract, the subthalamic nucleus, the interposed nucleus of the cerebellum, and in the inferior olive. In these areas the AT(2) recep tor gene expression corresponds well with [I-125]Sar(1)-ANG II binding . In addition, AT(2) receptor mRNA expression was found in the red nuc leus where no [I-125]Sar(1)-ANG II binding was present. No significant hybridization of the AT(2) receptor antisense probe was found in sept al nuclei, the locus coeruleus, the dorsolateral geniculate nucleus, o r the cerebellar cortex, areas rich in [I-125]Sar(1)-ANG II binding. O ur results indicate that some brain regions may be involved in AT(2) r eceptor formation, transporting the receptor protein to other brain ar eas. However, in most structures, both the formation and expression of receptors occur, suggesting the existence of local AT(2) receptor cir cuits, or that of AT(2) autoreceptors. Other structures express only t he receptor protein, indicating that these AT(2) receptors are produce d elsewhere. Our present data are the basis for further studies on the clarification of AT(2) receptor pathways in the brain.