Premium
Evidence for neuro‐effector transmission through postjunctional α 2 ‐adrenoceptors in human saphenous vein
Author(s) -
Docherty James R.,
Hyland Lisa
Publication year - 1985
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.1476-5381.1985.tb12942.x
Subject(s) - yohimbine , prazosin , stimulation , antagonist , endocrinology , medicine , chemistry , pharmacology , receptor
1 The effects of the α‐adrenoceptor antagonist prazosin and the α 2 ‐adrenoceptor antagonist yohimbine were examined against stimulation‐evoked contractions in human isolated saphenous veins. 2 The concentration of yohimbine producing 30% inhibition of stimulation‐evoked contractions (IC 30 ) was 13.2 n m , whereas the IC 30 of prazosin was greater than 250 n m . 3 The inhibition of stimulation‐evoked contractions by yohimbine was not prejunctionally mediated since yohimbine (0.01–0.1 μ m ) significantly potentiated the stimulation‐evoked overflow of tritium in tissues pre‐incubated with [ 3 H]‐noradrenaline. 4 The high potency of yohimbine and the low potency of prazosin indicate that neuro‐effector transmission in human saphenous vein is mediated predominantly by postjunctional α 2 ‐adrenoceptors.