5-HT4 receptors are not involved in the control of small intestinal transit in the fasted conscious rat
| Autor: | N. M. Clayton, Jeremy D. Gale |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Male
medicine.medical_specialty Metoclopramide Physiology Stimulation Bethanechol Zacopride chemistry.chemical_compound Internal medicine Intestine Small medicine Animals Receptor Gastrointestinal Transit Endocrine and Autonomic Systems digestive oral and skin physiology Gastroenterology Rats Inbred Strains Fasting Microspheres Rats Serotonin Receptor Agonists Atropine Endocrinology chemistry Cisapride Receptors Serotonin Receptors Serotonin 5-HT4 Serotonin Antagonists Acetylcholine medicine.drug |
| Zdroj: | Neurogastroenterology and motility : the official journal of the European Gastrointestinal Motility Society. 8(1) |
| ISSN: | 1350-1925 |
| Popis: | Cisapride and metoclopramide are used clinically in the treatment of gastro-oesophageal reflux disease and also in a variety of motility disorders of the gastrointestinal tract. Their prokinetic effect is thought to be due to the augmentation of acetylcholine release from the myenteric plexus, an effect likely to be mediated through the stimulation of 5-HT4 receptors. The role of 5-HT4 receptors in the control of intestinal motility in man and animals is not clear, therefore we have investigated their role in the control of small intestinal transit in the rat. Radioactive microspheres were administered into the proximal duodenum of fasted conscious rats through an indwelling cannula. The extent of small intestinal transit was examined by determining the distribution of the microspheres within the intestine. Following i.p. injection small intestinal transit was inhibited (78%) by atropine (3 mg/kg), suggesting the presence of a basal cholinergic influence. Furthermore, in the presence of p-amino clonidine intestinal transit was stimulated (126%) by bethanechol (3 mg/kg). The 5-HT4 receptor agonists cisapride (1.0 mg/kg) and zacopride (1.0 mg/kg) failed to increase small intestinal transit. The 5-HT4 receptor selective antagonist GR125487 (1 mg/kg) was also without effect. These data suggest that 5-HT4 receptors are not involved in the control of small intestinal transit in the fasted conscious rat. |
| Databáze: | OpenAIRE |
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