Quantitative analysis of exocytosis directly visualized in living chromaffin cells.
Chromaffin cells isolated from the bovine adrenal medulla were observed under a Nomarski microscope through a CCD camera and an image processor. Exocytotic events of individual granules including fusion, extrusion, swelling, omega-figure formation, and membrane retrieval were visualized in individual cells stimulated by acetylcholine or K-rich solution. Initial steps were quicker than 16 ms, and the membrane retrieval was slower than 1-60 s. These findings provided a light microscopic proof for the exocytosis hypothesis as well as a basis for quantification of hormonal release. The technique was used to demonstrate significant secretion induced by a muscarinic agonist.
Terakawa
S
S
Department of Cell Physiology, National Institute for Physiological Sciences, Okazaki, Japan.
Fan
J H
JH
Kumakura
K
K
Ohara-Imaizumi
M
M
D000109:Acetylcholine / Q000494:pharmacology; D000313:Adrenal Medulla / Q000166:cytology / Q000502:physiology*; D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D002837:Chromaffin Granules / Q000502:physiology* / Q000648:ultrastructure; D005089:Exocytosis / Q000187:drug effects; D007700:Kinetics; D008564:Membrane Potentials / Q000187:drug effects; D009538:Nicotine / Q000494:pharmacology; D010095:Oxotremorine / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D014741:Video Recording
D010095:Oxotremorine; D009538:Nicotine; D000109:Acetylcholine; D011188:Potassium