High potassium-induced glutamate release in the cochlea: in vivo microdialysis study combined with on-line enzyme fluorometric detection of glutamate.
The time course of changes in perilymphatic glutamate release and their Ca2+-dependency were studied in the guinea pig cochlea during high K+-evoked depolarization. The glutamate concentration was analyzed continuously by an enzyme-linked fluorometric assay combined with microdialysis. Two peaks of glutamate increase were found in response to perfusion for 10 min. In the absence of Ca2+, the first peak was diminished, whereas the inhibition of the second peak was minimal.
Matsuda
K
K
Department of Otorhinolaryngology, Miyazki Medical College, 5200 Kihara, Kiyotake-cho, Miyazaki 889-16, Japan.
Ueda
Y
Y
Haruta
A
A
Tono
T
T
Komune
S
S
D000818:Animals; D003051:Cochlea / Q000187:drug effects* / Q000378:metabolism; D005470:Fluorometry / Q000379:methods; D005969:Glutamate Dehydrogenase; D018698:Glutamic Acid / Q000378:metabolism*; D006168:Guinea Pigs; D008564:Membrane Potentials / Q000187:drug effects; D017551:Microdialysis; D009862:Online Systems; D011188:Potassium / Q000494:pharmacology*
D018698:Glutamic Acid; D005969:Glutamate Dehydrogenase; D011188:Potassium