Nondepolarizing neuromuscular blockers inhibit the serotonin-type 3A receptor expressed in xenopus oocytes

Kyeong T. Min, Christopher L. Wu, Jay Yang

Research output: Contribution to journalArticlepeer-review

7 Scopus citations


Molecular cloning and sequence comparison indicates a high degree of structural homology between muscle nicotinic acetylcholine (nACh) and serotonin-type 3 (5HT(3A)) receptors, both members of the direct ligand-gated family of ion channels. Because of the structural similarities and common evolutionary origin of these receptors, neuromuscular blockers (competitive nACh antagonists) may demonstrate pharmacologic cross talk and exhibit attributes of 5-HT(3A) receptor antagonists. We examined six clinically-used neuromuscular blockers for their ability to antagonize currents flowing through the 5-HT(3A) receptors in voltage clamped Xenopus oocytes. The neuromuscular blockers reversibly inhibited the 5-HT(3A) receptor-gated current in the rank order potency of (IC50 mean ± SEM): d-tubocurarine (0.046 ± 0.003 μM), atracurium (0.40 ± 0.03 μM), mivacurium (15.1 ± 2.93 μM), vecuronium (16.3 ± 2.24 μM), and rocuronium (19.5 ± 2.31 μM). Gallamine was essentially inactive as a 5-HT(3A) receptor antagonist with an extrapolated IC50 of 1170 μM. We demonstrate that drugs classically known as competitive nACh receptor antagonists also block 5-HT(3A) receptors. It is likely that certain neuromuscular blockers share pharmacological properties with 5-HT(3A) receptor antagonists, such as a reduction in postoperative nausea and vomiting. With careful drug selection, pharmacological cross talk could potentially be used to minimize polypharmacy and optimize patient management. Implications: Muscle nicotinic acetylcholine and serotonin-type 3A (5-HT(3A)) receptors are similar. Therefore neuromuscular relaxants may block 5-HT(3A) receptors. Our pharmacological study demonstrates that neuromuscular relaxants, as with ondansetron, are 5-HT(3A) receptor antagonists. It is likely that certain neuromuscular relaxants exhibit ondansetron-like clinical properties, such as reduction in postoperative nausea and vomiting.

Original languageEnglish (US)
Pages (from-to)476-481
Number of pages6
JournalAnesthesia and analgesia
Issue number2
StatePublished - 2000
Externally publishedYes

ASJC Scopus subject areas

  • Anesthesiology and Pain Medicine


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