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Secretion of Catecholamines from Individual Adrenal Medullary Chromaffin Cells
Author(s) -
Leszczyszyn David J.,
Jankowski Jeffrey A.,
Viveros O. Humberto,
Diliberto Emanuel J.,
Near Joseph A.,
Wightman R. Mark
Publication year - 1991
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1991.tb03441.x
Subject(s) - adrenal medulla , secretion , chromaffin cell , endocrinology , medicine , catecholamine , medullary cavity , biology
Abstract: Catecholamine secretion has been measured with electrochemical techniques from isolated, single adrenal medullary chromaffin cells with carbon‐fiber microelectrodes. The electrode tip, which is of similar dimensions to the cell, is placed adjacent to the cell to enable the measurement of local secretion. Secretion is caused by exposing the cell to nanoliter volumes of solution containing nicotinic receptor agonists or depolarizing agents. The identification of secreted substances is made with cyclic voltammetry at both bare electrodes and electrodes coated with a perfluorinated cationexchange polymer. Catecholamine secretion is induced by nicotine (10–500 μ M ), carbamylcholine (1 m M ), and K + (60 m M ). All agents that induce secretion lead to a broad envelope of secreted catecholamines on which sharp concentration spikes are superimposed. The concentration spikes can be monitored with a time resolution of tens of milliseconds when the electrodes are used in the amperometric mode. Release induced by nicotine and K + is inhibited by Cd 2+ (0.5 m M ), and hexamethonium selectively blocks the nicotineinduced secretion. The actions of nicotine are found to continue for a longer period of time than those of the other secretagogues tested.