Swelling-induced catecholamine secretion recorded from single chromaffin cells.
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.
Moser
T
T
Abteilung Membranbiophysik, Max-Planck-Institut für Biophysikalische Chemie, Göttingen, Germany.
Chow
R H
RH
Neher
E
E
D000818:Animals; D002395:Catecholamines / Q000378:metabolism*; D002417:Cattle; D048429:Cell Size / Q000502:physiology; D002478:Cells, Cultured; D002838:Chromaffin System / Q000166:cytology / Q000378:metabolism*; D004594:Electrophysiology; D005089:Exocytosis / Q000502:physiology; D016257:Fura-2; D008564:Membrane Potentials / Q000502:physiology; D009994:Osmolar Concentration; D018408:Patch-Clamp Techniques
D002395:Catecholamines; D016257:Fura-2