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The effects of (−)‐daurisoline on Ca 2+ influx in presynaptic nerve terminals
Author(s) -
Lu Y. Ming,
Liu G. Qing
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.tb12086.x
Subject(s) - verapamil , chemistry , antagonist , free nerve ending , calcium , endocrinology , synaptosome , aorta , cerebral cortex , medicine , biophysics , biochemistry , biology , receptor , organic chemistry
1 The effects of (−)‐daurisoline on 45 Ca 2+ uptake and [ 3 H]‐γ‐aminobutyric acid ([ 3 H]‐GABA) release from synaptosomes of rat cerebral cortex and on contractile activity of rat aorta were examined. 2 Application of (−)‐daurisoline (1–100 μ m ) produced concentration‐related inhibition of high K + ‐stimulated 45 Ca 2+ uptake and [ 3 H]‐GABA release (IC 50 = 7.7 ± 0.9 μ m and 10.0 ± 1.5 μ m , respectively) in synaptosomes but verapamil was only weakly active. 3 Neither (−)‐daurisoline (100 μ m ) nor verapamil (100 μ m ) modified 45 Ca 2+ uptake in control medium (5 mM K + , resting uptake) and [ 3 H]‐GABA release in Ca‐free medium (45 mM K + basal release). 4 High K + and noradrenaline‐evoked contractions of rat aorta were inhibited by both (−)‐daurisoline and verapamil. 5 In conclusion, (−)‐daurisoline, which differed from verapamil in its mode of blocking Ca 2+ influx may be a potent Ca 2+ antagonist of Ca 2+ channels in neurones.