Moser T, Chow R H, Neher E
Abteilung Membranbiophysik, Max-Planck-Institut für Biophysikalische Chemie, Göttingen, Germany.
Pflugers Arch. 1995 Dec;431(2):196-203. doi: 10.1007/BF00410191.
We have studied osmotically induced catecholamine secretion from bovine adrenal chromaffin cells by combining patch-clamp measurements, electrochemical detection of secretion, and Fura-2 measurements of intracellular free calcium concentration ([Ca2+]i). We find that osmotically induced catecholamine release is exocytotic and calcium dependent. Furthermore, we demonstrate that cell swelling is coupled to such secretion via a volume-activated current, carrying predominantly chloride, which causes a plateau depolarization of the cell membrane potential and thus promotes voltage-activated calcium influx. Therefore, cell volume changes may modulate the secretory activity.
我们通过结合膜片钳测量、分泌的电化学检测以及用Fura-2测量细胞内游离钙浓度（[Ca2+]i），研究了渗透压诱导的牛肾上腺嗜铬细胞儿茶酚胺分泌。我们发现，渗透压诱导的儿茶酚胺释放是胞吐性的且依赖于钙。此外，我们证明细胞肿胀通过一种主要携带氯离子的容积激活电流与这种分泌相偶联，该电流导致细胞膜电位出现平台期去极化，从而促进电压激活的钙内流。因此，细胞体积变化可能调节分泌活动。
