Activation of dopamine D-4 receptors by ABT-724 induces penile erection in rats

Summary, in English

Apomorphine, a nonselective dopamine receptor agonist, facilitates penile erection and is effective in patients suffering from erectile dysfunction. The specific dopamine receptor subtype(s) responsible for its erectogenic effect is not known. Here we report that the dopamine D-4 receptor plays a role in the regulation of penile function. ABT-724 is a selective dopamine D4 receptor agonist that activates human dopamine D-4 receptors with an EC50 of 12.4 nM and 61% efficacy, with no effect on dopamine D-1, D-2, D-3, or D-5 receptors. ABT-724 dose-dependently facilitates penile erection when given s.c. to conscious rats, an effect that is blocked by haloperidol and clozapine but not by domperidone. A proerectile effect is observed after intracerebroventricular but not intrathecal administration, suggesting a supraspinal site of action. s.c. injections of ABT-724 increase intracavernosal pressure in awake freely moving rats. In the presence of sildenafil, a potentiation of the proerectile effect of ABT-724 is observed in conscious rats. The ability of ABT-724 to facilitate penile erection together with the favorable side-effect profile indicates that ABT-724 could be useful for the treatment of erectile dysfunction.

• Author: JD Brioni; RB Moreland; M Cowart; GC Hsieh; AO Stewart; Petter Hedlund; DL Donnelly-Roberts; M Nakane; JJ Lynch; T Kolasa; JS Polakowski; MA Osinski; K Marsh; Karl-Erik Andersson; JP Sullivan
• Department/s: Division of Clinical Chemistry and Pharmacology
• Publishing year: 2004
• Language: English
• Pages: 6758-6763
• Publication/Series: Proceedings of the National Academy of Sciences
• Volume: 101
• Issue: 17
• Links: http://dx.doi.org/10.1073/pnas.0308292101
• Document type: Journal article
• Publisher: National Academy of Sciences
• Topic: Medicinal Chemistry; Pharmacology and Toxicology
• Status: Published
• ISBN/ISSN/Other: ISSN: 1091-6490