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A calcium ionophore stimulating the secretion of catecholamines from the cat adrenal.
Author(s) -
Garcia A G,
Kirpekar S M,
Prat J C
Publication year - 1975
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.1975.sp010795
Subject(s) - ionophore , calcium , endocrinology , chemistry , medicine , stimulation , secretion , biochemistry , biology
1. Experiments were performed on perfused cat adrenal glands to examine the effect of a calcium ionophore A‐23187 in the secretion of catecholamines. 2. Ionophore (1–10 muM) caused a dose‐dependent release of catecholamines and the output was about 100‐fold greater at 10 mum than at 1 mum. 3. Release of catecholamines by the ionophore was dependent on the calcium concentration of the perfusion medium. Omission of calcium blocked the response to the ionophore while excess calcium facilitated it. 4. Magnesium antagonized the secretory response to the ionophore. Excess calcium overcame the inhibitory effect of magnesium. 5. The ionophore did not modify release of catecholamines by induced splanchnic nerve stimulation. 6. The results suggest that the ionophore, like depolarization, introduces calcium into the chromaffin cell to cause release of catecholamines.