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Effect of quinine on the release of catecholamines from bovine cultured chromaffin cells
Author(s) -
Tang R.,
Novas M.L.,
Glavinović M.I.,
Trifaró J.M.
Publication year - 1990
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1990.tb12966.x
Subject(s) - quinine , extracellular , catecholamine , depolarization , chromaffin cell , stimulation , endocrinology , chemistry , membrane potential , medicine , biophysics , biology , biochemistry , adrenal medulla , immunology , malaria
1 The effects of quinine on catecholamine release from cultured bovine chromaffin cells were studied. 2 Quinine (25–400 μ m ) produced a dose‐related inhibition of catecholamine release in response to depolarizing concentrations (12.5–50 m m ) of K + . 3 The inhibition of the secretory response to high K + produced by quinine decreased with the increase in the extracellular concentration of Ca 2+ . 4 Stimulation of cultured chromaffin cells with 50 m m K + produced a significant increase in Ca 2+ influx. In the presence of 100 μ m quinine a 54% inhibition of the K + ‐induced Ca 2+ influx was observed. 5 Quinine treatment of chromaffin cell cultures produced a small but significant decrease in membrane resting potential and a less pronounced depolarization in response to 50 m m K + . 6 The results suggest that the inhibition of the K + ‐evoked release of catecholamines produced by quinine is at least partly due to a decrease in Ca 2+ influx. Ca 2+ influx is lower because quinine reduces the sensitivity of the membrane potential to changes in extracellular K + but direct effects of quinine on Ca 2+ channels cannot be excluded.