PMID: 8938671Nov 1, 1996Paper

Presynaptic imidazoline receptors and alpha 2-adrenoceptors in the human heart: discrimination by clonidine and moxonidine

Naunyn-Schmiedeberg's Archives of Pharmacology
J LikunguM Göthert

Abstract

The involvement of presynaptic alpha 2-autoreceptors and imidazoline receptors in the modulation of noradrenaline release was investigated in strips from human atrial appendages preincubated with [3H]noradrenaline and superfused with medium containing desipramine and corticosterone. Electrical impulses were applied transmurally at 2 Hz. The imidazoline derivatives moxonidine and clonidine reduced to evoked tritium overflow in a concentration-dependent manner. Moxonidine was 18-fold more potent than clonidine. The concentration-response curve for moxonidine, but not for clonidine was shifted to the right by the alpha 2-adrenoceptor antagonist rauwolscine. The apparent pA2 value of rauwolscine against moxonidine was 8.41. An inhibitory effect was also observed for the imidazoline derivative BDF 6143 (4-chloro-2-(2-imidazolin-2-ylamino)-isoindoline), a mixed alpha 2-adrenoceptor antagonist/imidazoline receptor agonist; BDF 6143 was about 2-fold more potent than clonidine. Rauwolscine (1 microM) did not substantially shift the concentration-response curve of BDF 6143. It is concluded that noradrenaline release in the human atrium is inhibited not only via presynaptic alpha 2-autoreceptors but also via presynaptic non-I1, non-I2 imi...Continue Reading

Citations

Jan 15, 1999·General Pharmacology·G J Molderings, M Göthert
Jul 17, 2001·British Journal of Pharmacology·W RaaschP Dominiak
Jul 23, 1999·Annals of the New York Academy of Sciences·M GöthertG J Molderings
May 5, 2001·Expert Opinion on Pharmacotherapy·S A Doggrell
Dec 3, 2016·Pharmacology & Therapeutics·Eberhard Schlicker, Thomas Feuerstein
May 20, 2003·Pharmacology & Toxicology·Manfred Göthert
May 16, 2021·Naunyn-Schmiedeberg's Archives of Pharmacology·H BönischE Schlicker

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