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ID 32935
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Author
Hobara, Narumi
Goda, Mitsuhiro
Yoshida, Namika
Mio, Mitsunobu
Abstract

The present study was designed to investigate involvement of angiotensin (Ang) II type 2 receptors (AT2 receptors) in restoration of perivascular nerve innervation injured by topical phenol treatment. Male Wistar rats underwent in vivo topical application of 10% phenol around the superior mesenteric artery. After phenol treatment, animals were subjected to immunohistochemistry of the third branch of small arteries, Western blot analysis of AT2 receptor protein expression in dorsal root ganglia (DRG) and studies of mesenteric neurogenic vasoresponsiveness. Ang II (750 ng/kg/day), nerve growth factor (NGF; 20 μg/kg/day) and PD123,319 (AT2 receptor antagonist; 10 mg/kg/day) were intraperitoneally administered for 7 days using osmotic mini-pumps immediately after topical phenol treatment. Losartan (AT1 receptor antagonist) was administered in drinking water (0.025%). Phenol treatment markedly reduced densities of both calcitonin gene-related peptide (CGRP)-like immunoreactivity (LI)- and neuropeptide Y (NPY)-LI-containing fibers. NGF restored densities of both nerve fibers to the Sham control level. Coadministration of Ang II and losartan significantly increased the density of CGRP-LI-fibers but not NPY-LI-fibers compared with saline control. The increase of the density of CGRP-LI-fibers by coadministration of Ang II and losartan was suppressed by adding PD123,319. Coadministration of Ang II and losartan ameliorated reduction of CGRP nerve-mediated vasodilation of perfused mesenteric arteries caused by phenol treatment. The AT2 receptor protein expression detected in DRG was markedly increased by NGF. These results suggest that selective stimulation of AT2 receptors by Ang II facilitates reinnervation of mesenteric perivascular CGRP-containing nerves injured by topical phenol application in the rat.

Keywords
Angiotensin II type 2 receptors
Phenol-induced perivascular nerve injury
Calcitonin gene-related peptide-containing nerves
Neuropeptide Y-containing nerves
Neurotrophic
Rat mesenteric artery
Note
Published with permission from the copyright holder.
This is a author's copy,as published in NEUROSCIENCE , 2007, volume 150, issue 3, pp730-741.
Publisher URL: http://dx.doi.org/10.1016/j.neuroscience.2007.09.026
Direct access to Thomson Web of Science record
Copyright © 2007 by the National Academy of Sciences
Published Date
2008-05-28
Publication Title
Neuroscience
Volume
volume150
Issue
issue3
Start Page
730
End Page
741
Content Type
Journal Article
language
英語
Refereed
True
DOI
Web of Sience KeyUT
Submission Path
neuroscience/2