EFFERENT NEUROTRANSMITTERS AND INTRACELLULAR CA2+ CONCENTRATIONS IN INNER HAIR-CELLS OF GUINEA-PIG

被引：12
作者：
YAMASHITA, T
AMANO, H
KUMAZAWA, T
机构：
[1] Department of Otolaryngology, Kansai Medical University, Osaka
来源：
ORL-JOURNAL FOR OTO-RHINO-LARYNGOLOGY AND ITS RELATED SPECIALTIES | 1993年 / 55卷 / 04期
关键词：
ACETYLCHOLINE; ATP; INTRACELLULAR CA2+ CONCENTRATION; INNER HAIR CELL; GUINEA PIG;
D O I：
10.1159/000276422
中图分类号：
R76 [耳鼻咽喉科学];
学科分类号：
100213 ;
摘要：
To elucidate efferent inhibitory mechanisms of the cochlear inner hair cells (IHCs), the effects of candidate efferent neurotransmitters on intracellular Ca2+ concentrations ([CA2+]i) in the isolated IHCs of guinea pig were determined using the Ca2+ sensitive dye fura-2 and digital imaging microscopy. In the presence of 1 mM acetylcholine (ACh), there was a gradual and reversible increase in [Ca2+]i. In the presence of 10 muM ATP, there was a rapid and marked rise in [Ca2+]i. Thus. both ACh and ATP seem to be efferent neurotransmitters in IHCs of guinea pig. The ATP-induced elevation of [Ca2+]i in IHCs was suppressed when ACh was concomitantly applied; therefore, ACh may act as an antagonist of ATP-induced Ca2+ entry. With the independent addition of 10 muM calcitonin gene-related peptide and 10 muM enkephalin, there were no significant increases in [Ca2+]i. These neuropeptides are putative candidates for the efferent neuromodulators in IHCs of the guinea pig.
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页码：201 / 204
页数：4
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