Structures and pathways of the central nervous system are potentially involved in the serotonergic modulation of gastrointestinal activity.
The supposed involvement of rat brain regions in the modulation of rat small intestine serotonergic activity was investigated. Small electrolytic lesions were placed in the areas of medulla oblongata and pons Varoli; one week later, changes in the serotonergic response of the intestine were detected. The contractions mediated by the activation of 5-HT2 receptors in the proximal ileum were investigated. The whole ileum segments were cut and placed into the bath. The preparations were contracted by adding increasing concentrations of 5-hydroxytryptamine (5-HT) (10 nM-1 microM) and noncumulative concentration-response curves (CRCs) were established. The differences between 5-HT responses of preparations from either sham-operated or experimental rats suggest the existence of brainstem regions (dorsal vagal and solitary nuclei, parvocellular reticular nuclei and serotonergic A1,2,5 groups) that either stimulate or inhibit 5-HT modulatory action in the rat gastrointestinal tract.
Sevcík
J
J
Institute of Pharmacology, Prague, Czech Republic. h.sevcik@telecom.cz
Petrovický
P
P
Růzicka
V
V
Slánský
J
J
Masek
K
K
D000818:Animals; D001931:Brain Mapping / Q000379:methods; D001933:Brain Stem / Q000737:chemistry / Q000293:injuries / Q000378:metabolism / Q000502:physiology; D002490:Central Nervous System / Q000737:chemistry* / Q000378:metabolism*; D004064:Digestive System / Q000294:innervation*; D004068:Digestive System Physiological Phenomena; D004305:Dose-Response Relationship, Drug; D007082:Ileum / Q000294:innervation / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D008784:Methysergide / Q000494:pharmacology; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D011985:Receptors, Serotonin / Q000378:metabolism / Q000502:physiology; D012701:Serotonin / Q000494:pharmacology / Q000502:physiology*; D012702:Serotonin Antagonists / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology
D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; D012701:Serotonin; D008784:Methysergide