Harada N, Ernst A, Zenner H P
Department of Otolaryngology, University of Tübingen, Germany.
Acta Otolaryngol Suppl. 1993;500:39-41. doi: 10.3109/00016489309126176.
Single outer hair cells (OHCs) isolated from the guinea pig cochlea showed a regulatory volume decrease (RVD) after the initial cells swelling despite continued exposure to a hypotonic solution. The accompanying change of the intracellular Ca2+ concentration ([Ca2+]i) in the OHCs was investigated using the Ca(2+)-sensitive dye fura-2. Hyposmotic activation led to a [Ca2+]i increase which was accompanied by cell shortening and swelling. In a nominally Ca(2+)-free solution, however, [Ca2+]i was not significantly increased during hyposmotic activation although shortening and swelling of the OHCs were observed. These results suggest that the increase in [Ca2+]i during hyposmotic activation is mainly based on an influx of extracellular Ca2+.
从豚鼠耳蜗分离出的单个外毛细胞（OHCs），在最初细胞肿胀后，尽管持续暴露于低渗溶液中，仍表现出调节性容积减小（RVD）。使用钙敏感染料fura-2研究了OHCs中细胞内Ca2+浓度（[Ca2+]i）的伴随变化。低渗激活导致[Ca2+]i增加，同时伴有细胞缩短和肿胀。然而，在名义上无Ca2+的溶液中，尽管观察到OHCs缩短和肿胀，但在低渗激活期间[Ca2+]i并未显著增加。这些结果表明，低渗激活期间[Ca2+]i的增加主要基于细胞外Ca2+的内流。
