Tropisetron-d5

Tropisetron-d5 is intended for use as an internal standard for the quantification of tropisetron (Item No. 21240) by GC- or LC-MS. Tropisetron is an antagonist of the serotonin (5-HT) receptor subtype 5-HT3 (Ki = 0.8 nM for the mouse receptor).{58017} It is selective for 5-HT3 over the 5-HT4 receptor subtype (Ki = 156 nM for the porcine receptor). Tropisetron is also an antagonist of the a9 nicotinic acetylcholine receptor (nAChR; IC50 = 166 nM for the rat receptor) and a partial agonist of the a7 nAChR (Ki = 6.9 nM for the rat receptor).{33370,65094} It enhances glycine-induced potentiation of homomeric a1 but not homomeric a2 glycine receptors when used at a concentration of 10 µM.{65095} Tropisetron (0.1 nM) blocks 5-HT-induced depolarizations in isolated rabbit nodose ganglia.{33371} It exhibits anti-emetic effects in a ferret model of emesis induced by cisplatin (Item No. 13119) when administered at a dose of 1 mg/kg.{46650} Formulations containing tropisetron have been used in the treatment of nausea and vomiting associated with chemotherapy.