Expression of Na+/myo-inositol cotransporter mRNA in the inner ear of the rat.
We have demonstrated the cellular localization of Na+/myo-inositol cotransporter (SMIT) mRNA in the rat inner ear by in situ hybridization. In the cochlea, the most intense SMIT mRNA signals were observed in fibrocytes of the spiral ligament, moderate signals were found in the spiral limbus, inner hair cells and spiral ganglion cells, while the hybridization signals were almost undetectable in the marginal cells of the stria vascularis and outer hair cells. In the vestibular system, moderate hybridization signals were found in the sensory epithelium, fibrocytes and vestibular ganglion cells. These findings suggest that SMIT plays an important role in maintenance of intracellular ionic balance and cell volume in the inner ear, especially in the fibrocytes associated with generation of the ion gradients between the endolymph and perilymph.
Minami
Y
Y
Department of Otolaryngology, Nara Medical University, Japan.
Shimada
S
S
Inoue
K
K
Morimura
H
H
Miyai
A
A
Yamauchi
A
A
Matsunaga
T
T
Tohyama
M
M
D000818:Animals; D001345:Autoradiography; D002352:Carrier Proteins / Q000096:biosynthesis*; D003051:Cochlea / Q000378:metabolism; D007758:Ear, Inner / Q000166:cytology / Q000378:metabolism*; D015870:Gene Expression; D006360:Heat-Shock Proteins / Q000096:biosynthesis*; D017403:In Situ Hybridization; D007294:Inositol / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins; D009928:Organ Specificity; D015347:RNA Probes; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats; D017208:Rats, Wistar; D012964:Sodium / Q000378:metabolism; D013462:Sulfur Radioisotopes; D027981:Symporters; D014722:Vestibule, Labyrinth / Q000378:metabolism
D002352:Carrier Proteins; D006360:Heat-Shock Proteins; D008565:Membrane Proteins; D015347:RNA Probes; D012333:RNA, Messenger; D013462:Sulfur Radioisotopes; D027981:Symporters; C073884:SLC5A3 protein, human; D007294:Inositol; D012964:Sodium