Receptor binding properties of amperozide

Summary, in English

The receptor pharmacology of amperozide was investigated with in vitro radioligand binding technique. Amperozide possessed a high affinity to the 5-HT2 receptors (Ki = 16.5 +/- 2.1 nM) and a moderate affinity to alpha 1-adrenergic receptors of rat cerebral cortical membranes (Ki = 172 +/- 14 nM). The affinity of amperozide for striatal and limbic dopamine D2 receptors was low and not significantly different (Ki +/- S.E.M. = 540 +/- 59 nM vs 403 +/- 42 nM; p less than 0.11, n = 4). The affinity for striatal and limbic 5-HT2 receptors was measured as well and found to be very close to the affinity to the cerebral cortical 5-HT2 receptor. The drug affinity for D2 and 5-HT2 receptors seems thus not to be influenced by the location of the receptor moiety. The affinity for several other rat brain receptors such as 5-HT1A, alpha 2-adrenergic, dopamine D1, muscarinic M1 and M2, opiate sigma and beta 2-adrenergic was low. The pseudo-Hill coefficient of the amperozide competition binding curve was consistently higher than one indicating antagonistic and complex interactions with the 5-HT2 receptor or with alpha 1-adrenergic and dopamine D2 receptors. The antagonistic properties of amperozide were investigated by its ability to antagonize the serotonin-induced formation of inositol-1-phosphate in human blood platelets. Amperozide inhibited this 5-HT2 receptor-mediated intracellular response with similar potency as ketanserin. These results suggest that amperozide is a selective 5-HT2 receptor antagonist.

• Author: J Svartengren; Per Simonsson
• Department/s: Clinical Chemistry, Malmö
• Publishing year: 1990
• Language: English
• Pages: 8-11
• Publication/Series: Pharmacology and Toxicology
• Volume: 66
• Issue: Suppl. 1
• Document type: Journal article
• Publisher: Wiley-Blackwell
• Topic: Medicinal Chemistry
• Status: Published
• Research group: Clinical Chemistry, Malmö
• ISBN/ISSN/Other: ISSN: 1600-0773