A Ca-dependent early step in the release of catecholamines from adrenal chromaffin cells.
Intense stimuli, such as trains of depolarizing pulses or the caffeine-induced release of calcium from intracellular stores, readily depress the secretory response in neuroendocrine cells. Secretory responses are restored by rest periods of minutes in duration. This recovery was accelerated when the concentration of cytosolic calcium was moderately increased and probably resulted from calcium-dependent replenishment of a pool of release-ready granules. Continuously increased concentrations of calcium led the over-filling of such a pool. Subsequently, secretory responses to stronger calcium stimuli were augmented. Hormone-induced calcium transients with a plateau phase of increased concentration of calcium may enhance the secretory response in this way.
von Rüden
L
L
Department of Membrane Biophysics, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany.
Neher
E
E
D000313:Adrenal Medulla / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D001920:Bradykinin / Q000494:pharmacology; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002395:Catecholamines / Q000378:metabolism*; D002417:Cattle; D002478:Cells, Cultured; D002837:Chromaffin Granules / Q000187:drug effects / Q000378:metabolism*; D004553:Electric Conductivity; D006632:Histamine; D008564:Membrane Potentials; D008954:Models, Biological; D009761:Nystatin / Q000494:pharmacology
D002395:Catecholamines; D009761:Nystatin; D002110:Caffeine; D006632:Histamine; D001920:Bradykinin; D002118:Calcium