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. 1985 Feb;84(2):573–576. doi: 10.1111/j.1476-5381.1985.tb12942.x

Evidence for neuro-effector transmission through postjunctional alpha 2-adrenoceptors in human saphenous vein.

J R Docherty, L Hyland
PMCID: PMC1987305  PMID: 2983815

Abstract

The effects of the alpha 1-adrenoceptor antagonist prazosin and the alpha 2-adrenoceptor antagonist yohimbine were examined against stimulation-evoked contractions in human isolated saphenous veins. The concentration of yohimbine producing 30% inhibition of stimulation-evoked contractions (IC30) was 13.2 nM, whereas the IC30 of prazosin was greater than 250 nM. The inhibition of stimulation-evoked contractions by yohimbine was not prejunctionally mediated since yohimbine (0.01-0.1 microM) significantly potentiated the stimulation-evoked overflow of tritium in tissues pre-incubated with [3H]-noradrenaline. 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 alpha 2-adrenoceptors.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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