Interactions of trimebutine with guinea-pig opioid receptors.
Affinities of trimebutine (TMB) and N-desmethyl trimebutine (NDTMB) for mu, delta and kappa opioid receptor subtypes have been examined using specific 3H-ligands and guinea-pig membrane. TMB and NDTMB showed a relative higher affinity for the mu receptor subtype although they were, respectively, 30- and 48-fold less active than morphine. The receptor selectivity index for mu, delta and kappa were 100:12:14.4 for TMB, 100:32:25 for NDTMB and 100:5:5 for morphine. The sodium shift ratio was 14 for TMB, 10 for NDTMB and 37 for morphine. These data show that (unlike morphine, a pure mu agonist) TMB and NDTMB can be classified as weak opioid agonists and confirm that peripheral opioid receptors mediate their gastrointestinal motility effects.
D000818:Animals; D001565:Benzoates / Q000378:metabolism*; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D011869:Radioligand Assay; D011957:Receptors, Opioid / Q000378:metabolism*; D014287:Trimebutine / Q000031:analogs & derivatives / Q000378:metabolism*
D001565:Benzoates; D011957:Receptors, Opioid; C053065:N-desmethyltrimebutine; D014287:Trimebutine