5-HT3 receptor antagonism by anpirtoline, a mixed 5-HT1 receptor agonist/5-HT3 receptor antagonist - PubMed (original) (raw)

5-HT3 receptor antagonism by anpirtoline, a mixed 5-HT1 receptor agonist/5-HT3 receptor antagonist

M Göthert et al. Br J Pharmacol. 1995 Jan.

Abstract

1. The aim of this study was to provide evidence that anpirtoline, which is an agonist at 5-HT1B and 5-HT1D receptors and also displays submicromolar affinity for 5-HT1A recognition sites, in addition, acts as an antagonist at 5-HT3 receptors. 2. In radioligand binding studies on rat brain cortical membranes, anpirtoline inhibited specific binding of [3H]-(S)-zacopride to 5-HT3 receptor recognition sites (pKi: 7.53). 3. In N1E-115 neuroblastoma cells in which [14C]-guanidinium was used as a tool to measure cation influx through the 5-HT3 receptor channel, the 5-HT-induced influx was concentration-dependently inhibited by anpirtoline. In this respect, anpirtoline mimicked other 5-HT3 receptor antagonists; the rank order of potency was ondansetron > anpirtoline > metoclopramide. 4. The concentration-response curve for 5-HT as a stimulator of [14C]-guanidinium influx was shifted to the right by anpirtoline (apparent pA2: 7.78). 5. In urethane-anaesthetized rats, anpirtoline inhibited (at lower potency than zacopride and tropisetron) the 5-HT- or phenylbiguanide-induced bradycardia (Bezold-Jarisch reflex), but did not induce this reflex by itself. 6. Intravenous infusion of cisplatin in the domestic pig caused a consistent emetic response which was antagonized by anpirtoline. 7. It is concluded that anpirtoline, which was previously characterized as a 5-HT1 receptor agonist also proved to be a 5-HT3 receptor antagonist in several experimental models and, hence, exhibits a unique pattern of properties at different 5-HT receptors.

PubMed Disclaimer

Similar articles

Cited by

References

    1. Br J Pharmacol. 1993 Feb;108(2):436-42 - PubMed
    1. J Pharmacol Exp Ther. 1992 Dec;263(3):1015-22 - PubMed
    1. J Neurochem. 1993 Jun;60(6):2059-67 - PubMed
    1. J Biol Chem. 1951 Nov;193(1):265-75 - PubMed
    1. Proc Natl Acad Sci U S A. 1972 Jan;69(1):258-63 - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources