Effects of Betahistine Metabolites on Frog Ampullar Receptors

Previous studies have demonstrated that betahistine, an histamine-like substance used widely as an anti-vertigo drug, can decrease ampullar receptor resting discharge without affecting their mechanically evoked responses. Pharmacokinetic studies have shown that this drug is transformed, mainly at th...

Full description

Saved in:
Bibliographic Details
Published in:Acta oto-laryngologica 2000, Vol.120 (1), p.25-27
Main Author: Laura Botta, Eugenio Mira, Stefano Valli, Gianpiero Zucca, Paola Perin, Claudio Benvenuti, Antonio Fossati, Paolo Valli
Format: Article
Language:English
Subjects:
Animals
Anti-vertigo Drugs Betahistine Betahistine Metabolites Vertigo Vestibular System
Betahistine - analysis
Betahistine - pharmacology
Biological and medical sciences
Calorimetry - methods
Ear, auditive nerve, cochleovestibular tract, facial nerve: diseases, semeiology
Ent. Stomatology
Histamine Agonists - pharmacology
Medical sciences
Non tumoral diseases
Otorhinolaryngology. Stomatology
Pharmacology. Drug treatments
Pyridines - analysis
Pyridines - pharmacology
Rana esculenta
Receptors, Drug - drug effects
Space life sciences
Vestibule, Labyrinth - chemistry
Vestibule, Labyrinth - drug effects
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Previous studies have demonstrated that betahistine, an histamine-like substance used widely as an anti-vertigo drug, can decrease ampullar receptor resting discharge without affecting their mechanically evoked responses. Pharmacokinetic studies have shown that this drug is transformed, mainly at the hepatic level, into aminoethylpyridine (M1), hydroxyethylpyridine (M2), then excreted with the urine as pyridylacetic acid (M3). The goal of the present study was to investigate whether betahistine metabolites are also able to affect vestibular receptor activity. Results demonstrated that, in the range tested (10(-7)-10(-2) M), M2 and M3 exerted no effect, whereas M1, at concentrations higher than 10(-6) M, was able to reduce the resting discharge of ampullar receptors without affecting the evoked responses. M1 therefore exerts effects similar to those of betahistine on ampullar receptors. This might be of some clinical interest. On the basis of our data, the hypothesis may be put forward that the anti-vertigo action of betahistine is at first achieved by betahistine itself and then sustained by M1.
ISSN:0001-6489
1651-2251
DOI:10.1080/000164800760370783