Inhibitory effect of glucocorticoids on human-cloned 5-hydroxytryptamine3A receptor expressed in xenopus oocytes.

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Suzuki T, Sugimoto M, Koyama H, Mashimo T, Uchida I

Inhibitory effect of glucocorticoids on human-cloned 5-hydroxytryptamine3A receptor expressed in xenopus oocytes.

Anesthesiology. 2004 Sep;101(3):660-5.

PubMed ID

15329590 [ View in PubMed

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Abstract

BACKGROUND: Methylprednisolone, dexamethasone, and other glucocorticoids have been found effective against nausea and vomiting induced by chemotherapy and surgery. Although the specific 5-hydroxytriptamine3 (5-HT3) receptor antagonists such as ondansetron and ramosetron are used as antiemetics, reports show that the use of 5-HT3 receptor antagonists with some glucocorticoids brings additional effects. Glucocorticoids are reported to be antiemetic. The effect of glucocorticoids on 5-HT3 receptor, however, has not been well characterized. This study was designed to examine whether dexamethasone and methylprednisolone had direct effects on human-cloned 5-HT3A receptor expressed in Xenopus oocytes. METHODS: Homomeric human-cloned 5-HT3A receptor was expressed in Xenopus oocytes. The authors used the two-electrode voltage-clamping technique to study the effect of methylprednisolone and dexamethasone on 5-HT-induced current. RESULTS: Both dexamethasone and methylprednisolone concentration-dependently attenuated 5-HT-induced current. Dexamethasone inhibited 2 microm 5-HT-induced current, which was equivalent to EC30 concentration for 5-HT3A receptor, with an inhibitory concentration 50% of 5.29 +/- 1.02 microm. Methylprednisolone inhibited 2 microm 5-HT-induced current with an inhibitory concentration 50% of 1.07 +/- 0.15 mm. The mode of inhibition with either dexamethasone or methylprednisolone was noncompetitive and voltage-independent. When administered together with the 5-HT3 receptor antagonists, ramosetron or metoclopramide, both glucocorticoids showed an additive effect on 5-HT3 receptor. CONCLUSION: The glucocorticoids had a direct inhibitory effect on 5-HT3 receptors. The combined effect of glucocorticoids and the 5-HT3 receptor antagonists seems additive.

DrugBank Data that Cites this Article

Drug Targets

Drug	Target	Kind	Organism	Pharmacological Action	Actions
Ramosetron	5-hydroxytryptamine receptor 3A	Protein	Humans	Unknown	Antagonist	Details