Yamashita T, Amano H, Ohtani M, Harada N, Kumazawa T
Department of Otolaryngology, Kansai Medical University, Osaka, Japan.
Acta Otolaryngol. 1991;111(5):879-84. doi: 10.3109/00016489109138425.
Single inner hair cells of the guinea pig cochlea were isolated using enzymatic and mechanical techniques. The intracellular free calcium ion concentrations [( Ca2+]i) of the isolated inner hair cells were determined using the Ca2+ sensitive dye fura-2 and digital imaging microscopy. In the presence of 1 micron ionomycin, a Ca2+ ionophore, there was an irreversible increase in [Ca2+]i. The 150 mM KCl stimulation, which induces a depolarization, resulted in a temporary increase in [Ca2+]i. This increase in [Ca2+]i was not observed under conditions of depolarization, in Ca(2+)-free medium. These observations are interpreted to mean that the [Ca2+]i during membrane depolarization mainly originates from an influx of extracellular Ca2+ into the cytoplasm.
采用酶解和机械技术分离豚鼠耳蜗的单个内毛细胞。使用钙敏感染料fura-2和数字成像显微镜测定分离出的内毛细胞的细胞内游离钙离子浓度[Ca2+]i。在存在1微摩尔离子霉素（一种钙离子载体）的情况下，[Ca2+]i出现不可逆增加。150 mM KCl刺激可诱导去极化，导致[Ca2+]i暂时增加。在无钙培养基中去极化条件下未观察到[Ca2+]i的这种增加。这些观察结果被解释为意味着膜去极化期间的[Ca2+]i主要源于细胞外Ca2+流入细胞质。
