Role of 5-HT1-like receptors in the increase in intragastric pressure induced by 5-hydroxytryptamine in the rat
| Autor: | K. Mohan Dhasmana, Yin N. Zhu, P.R. Saxena, Sreekanth Tadipatri, Carlos M. Villalón |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Atropine
Male Agonist Serotonin medicine.medical_specialty Metergoline Indoles Ketanserin medicine.drug_class Methiothepin Tropisetron Mepyramine Methysergide chemistry.chemical_compound Catecholamines Internal medicine Pressure medicine Animals 5-HT receptor Pyrilamine Pharmacology Chemistry Stomach Rats Inbred Strains Receptor antagonist Rats Endocrinology Receptors Serotonin Female medicine.drug |
| Zdroj: | European Journal of Pharmacology. 213:293-299 |
| ISSN: | 0014-2999 |
| DOI: | 10.1016/0014-2999(92)90694-y |
| Popis: | The study concerned the effects of 5-hydroxytryptamine (5-HT) on intragastric pressure in bilaterally vagotomized spinal rats. Intravenous (i.v.) bolus injections of 5-HT (2.5, 5.0 and 10 micrograms/kg) produced dose-dependent increases in intragastric pressure; these effects were not modified by atropine (up to 0.2 mg/kg) or mepyramine (1 mg/kg), but were blocked by the mixed 5-HT1-like and 5-HT2 receptor antagonists, methiothepin (0.1, 0.3 and 0.5 mg/kg i.v.) and methysergide (0.5, 1 and 2.5 mg/kg i.v.). However, metergoline (0.5, 1 and 2 mg/kg i.v.) did not markedly modify this effect of 5-HT; only the response induced by 5 micrograms/kg 5-HT was significantly antagonized by the highest dose of metergoline. In contrast, neither the 5-HT2 receptor antagonist, ketanserin (0.5, 1 and 1.5 mg/kg i.v.), nor the 5-HT3 receptor antagonist, ICS 205-930 (0.5, 1 and 3 mg/kg i.v.), influenced the 5-HT-induced increase in intragastric pressure. In addition, 5-carboxamidotryptamine (25, 50 and 100 micrograms/kg i.v.) and RU 24969 (50, 100 and 200 micrograms/kg i.v.) mimicked the aforementioned effects of 5-HT but were weaker than 5-HT. These data suggest that the 5-HT-induced increase in intragastric pressure in the spinal and bilaterally vagotomized rat is mediated by an atypical 5-HT1-like receptor, which, based on the low agonist potency of 5-carboxamidotryptamine and RU 24969 and the resistance to blockade by metergoline, does not seem to correspond to either the 5-HT1A, 5-HT1B, 5-HT1C or the 5-HT1D receptor subtypes. |
| Databáze: | OpenAIRE |
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