Transient cochlear ischemia and its effects on the stria vascularis.
The effects of transient cochlear ischemia on the stria vascularis were studied. Fifteen minutes of ischemia decreased the endocochlear potential by up to 17.5 mV on day 1; it returned to normal on day 7. Immunostaining for Na+,K+-ATPase, a marker for the Na+/K+-pump, and for connexin 26, a marker for gap junctions, was inhibited on days 1 and 4, and returned to normal on day 7. Electron microscopy showed expansion of the intercellular space with abundant vacuolar formation in the stria vascularis. These morphological changes disappeared completely by day 7. The results indicate that transient ischemia causes a reversible functional disorder of the stria vascularis with fine structural changes, which may be owing to dysfunction of Na+/K+-pump or gap junctions.
Morizane
Isao
I
Department of Otolaryngology, Ehime University School of Medicine, Ehime, Japan.
Hakuba
Nobuhiro
N
Shimizu
Yoshitaka
Y
Shinomori
Yusuke
Y
Fujita
Kensuke
K
Yoshida
Tadashi
T
Shudou
Masachika
M
Gyo
Kiyofumi
K
D000818:Animals; D015834:Cochlear Diseases / Q000378:metabolism / Q000503:physiopathology*; D003055:Cochlear Microphonic Potentials / Q000502:physiology*; D000072259:Connexin 26; D017630:Connexins / Q000378:metabolism; D005849:Gerbillinae; D007150:Immunohistochemistry / Q000379:methods; D002546:Ischemic Attack, Transient / Q000378:metabolism / Q000503:physiopathology*; D008297:Male; D046529:Microscopy, Electron, Transmission / Q000379:methods; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013316:Stria Vascularis / Q000473:pathology / Q000502:physiology* / Q000648:ultrastructure; D013997:Time Factors
D017630:Connexins; D000072259:Connexin 26; D000254:Sodium-Potassium-Exchanging ATPase