Expression and immunohistochemical localization of adrenomedullin in the mouse cochlea.
Adrenomedullin (AM) is a novel hypotensive and vasodilator peptide. It has been shown that AM is biosynthesized in various organs and cells and is suggested to play multiple roles including electrolyte homeostasis and body fluid control. The present study describes for the first time the presence of mRNA for AM and AM-like immunoreactivity in the cochlea. A reverse transcription-polymerase chain reaction (RT-PCR) performed with gene-specific AM primer on total RNA extracted from mouse cochlea revealed a PCR product of the expected size. Immunohistochemical examination showed positive immunostaining in vascular smooth muscle cells of the modiolar arterioles and in the stria vascularis of the cochlea. These results suggest that AM may play a role in the regulation not only of cochlear hemodynamics but also of cochlear fluid dynamics.
Tono
Tetsuya
T
Department of Otolaryngology, Miyazaki Medical College, Miyazaki, Japan. tono@post.miyazaki-med.ac.jp
Shimozono
Masami
M
Kawano
Hirokazu
H
Asada
Yujiro
Y
Kitamura
Kazuo
K
Komune
Shizuo
S
D053607:Adrenomedullin; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D003051:Cochlea / Q000737:chemistry* / Q000166:cytology / Q000276:immunology*; D007150:Immunohistochemistry; D051379:Mice; D008813:Mice, Inbred ICR; D010455:Peptides / Q000032:analysis* / Q000276:immunology*; D012313:RNA / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013316:Stria Vascularis / Q000737:chemistry / Q000166:cytology
D000911:Antibodies, Monoclonal; D010455:Peptides; C034477:RNA primers; D012333:RNA, Messenger; D053607:Adrenomedullin; D012313:RNA