Pharmacological comparison of the effect of ibogaine and 18-methoxycoronaridine on isolated smooth muscle from the rat and guinea-pig.
British journal of pharmacology April 1, 2000 M K Mundey, N A Blaylock, R Mason et al. 6 citations
Ibogaine and 18-methoxycoronaridine, alkaloids with reported anti-addictive properties, modulated electrically-evoked contractions in smooth muscle preparations but did not selectively interact with mu-opioid receptors. In guinea-pig ileum, both drugs concentration-dependently inhibited cholinergic contractions (ibogaine pIC50 5.28, 18-methoxycoronaridine pIC50 5.05), an effect not blocked by naloxone. In rat vas deferens, they enhanced purinergic contractions and caused a 3- to 5-fold rightward shift of DAMGO-induced inhibition. In guinea-pig bladder, both drugs doubled the purinergic component of neurogenic contractions without affecting cholinergic contractions. Ibogaine, but not 18-methoxycoronaridine, enhanced spontaneous contractions of rat portal vein. The pronounced enhancement of purinergic contractions is a novel finding warranting further investigation.