Doi K, Mori N, Matsunaga T
Department of Otolaryngology, Osaka University Medical School, Japan.
Hear Res. 1990 Apr;45(1-2):157-63. doi: 10.1016/0378-5955(90)90192-r.
Endocochlear potential (EP) and cochlear microphonics (CM) were recorded during the perilymphatic perfusion with forskolin known as an adenylate cyclase stimulant. Forskolin produced a reversible EP elevation in a dose-dependent manner. Perfusion with 1,9-dideoxy-forskolin, an analogue of forskolin that does not stimulate adenylate cyclase, had no effect on EP, whereas perfusions with other agents that raise the cAMP-level (IBMX, a phosphodiesterase inhibitor, and dbcAMP) duplicated the effect of forskolin. The vigorous CM during the EP elevation and the large negative EP induced by anoxia superimposed on the elevated EP indicate that the K+ diffusion potential through the hair cell membrane cannot be altered by forskolin. The results suggest that the adenylate cyclase system in the stria vascularis and/or Reissner's membrane may modulate the generation of EP.
在内淋巴灌注被称为腺苷酸环化酶刺激剂的福斯高林过程中，记录了耳蜗内电位（EP）和耳蜗微音电位（CM）。福斯高林以剂量依赖的方式使EP产生可逆性升高。用1,9 - 二脱氧 - 福斯高林（一种不刺激腺苷酸环化酶的福斯高林类似物）进行灌注对EP没有影响，而用其他能提高环磷酸腺苷（cAMP）水平的药物（磷酸二酯酶抑制剂异丁基甲基黄嘌呤（IBMX）和二丁酰环磷腺苷（dbcAMP））进行灌注则重现了福斯高林的作用。EP升高期间强烈的CM以及叠加在升高的EP上的缺氧诱导的大的负性EP表明，福斯高林不能改变通过毛细胞膜的钾离子扩散电位。结果表明，血管纹和/或内耳膜中的腺苷酸环化酶系统可能调节EP的产生。
