Expression of thiazide-sensitive Na+-Cl- cotransporter in the rat endolymphatic sac.
The endolymphatic sac (ES) is a part of the membranous labyrinth and is believed to absorb endolymph. It has been well-established that the endolymph absorption is dependent on several ion transporters in a manner similar to that in the kidney, and the ES is regulated by hormones such as aldosterone and vasopressin that also affect on the kidney. The thiazide-sensitive Na(+), Cl(-) cotransporter (TSC) is an electroneutral cotransporter specific to the kidney that plays an important role in absorption of NaCl in renal tubules. In the inner ear, TSC expression has never been examined. The expression of TSC in the rat ES was examined by RT-PCR, in situ hybridization and immunohistochemistry. These analyses indicated that TSC genes and proteins were expressed in the rat ES. In contrast, it was not observed in the rat cochlea by RT-PCR. This is the first report confirming the expression of TSC in the ES.
Akiyama
Kosuke
K
Department of Otolaryngology, Faculty of Medicine, Kagawa University, Kita-gun Miki-cho Ikenobe 1750-1, Kagawa 761-0793, Japan. kakaka@med.kagawa-u.ac.jp
Miyashita
Takenori
T
Mori
Terushige
T
Inamoto
Ryuhei
R
Mori
Nozomu
N
D000818:Animals; D004712:Endolymphatic Sac / Q000737:chemistry / Q000378:metabolism*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D011955:Receptors, Drug / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D049992:Sodium Chloride Symporters / Q000032:analysis / Q000235:genetics / Q000378:metabolism*
D012333:RNA, Messenger; D011955:Receptors, Drug; D049992:Sodium Chloride Symporters; C064415:thiazide receptor