Biomaterial Database

The neural control of the serotonin content in mammalian enterochromaffin cells. 1979

G Pettersson

Serotonin (5-HT) in the mammalian gut is mainly stored in enterochromaffin cells (EC). Vagal or splanchnic nerve stimulation respectively increase portal blood levels of 5-HT and decrease 5-HT content in EC, suggesting a neural control of these cells. Previous studies have also suggested that the vagal effect is mediated via vagal adrenergic nerve fibers, since this effect could be blocked by sympathectomy, removal of the superior cervical sympathetic ganglia or by the administration of a beta-adrenoceptor blocking agent, d, 1-propranolol. In the present study the control of the 5-HT content in EC was studied by a cytofluorimetric method in specimens from rat duodenal mucosa after drug incubations and transmural field stimulation (TFS) in vitro: Incubations in a Krebs' solution containing adrenaline (A), noradrenaline (NA) or isoprenaline (IP) (10(-9)--10(-5) M) caused a decrease of the 5-HT content in EC. For NA and A this effect was concentration-dependent. The effect of A was antagonized by d, 1-propranolol but not by d-propranolol, metoprolol, phentolamine or phenoxybenzamine. This indicates that the effects observed were mediated via a true beta-adrenoceptor mechanism. Acetylcholine (ACh), in the presence of eserine, also decreased the 5-HT content in EC, but was less potent than the adrenergic substances. TFS decreased the 5-HT content of EC to about 75% of unstimulated control levels. The presence of tetrodotoxin or d, 1-propranolol in the stimulation bath antagonized the effect of TFS. In specimens from rats pretreated with 6-OH-dopamine, TFS had no effect. Thus, TFS appears to induce a release of 5-HT from EC mainly by activation of adrenergic nerves. The ultrastructural relationship between nerve terminals and EC was studied in the guinea-pig duodenum. Animals were pretreated with 5-OH-dopamine in order to visualize adrenergic nerves. Near the base of most of the EC examined, at least 3 different types of nerve terminals were observed with the appearance of adrenergic, cholinergic and peptidergic terminals. In addition, dendrite-like processes were demonstrated. No true synapse on EC was found, but the minimal distance between the nerve terminals and EC was 150-250 nm, well within the limits of the "autonomic gap", suggesting a functional neural influence on these cells. The importance of the demonstrated beta-adrenergic control of EC was further studied in vivo. Efferent vagal nerve stimulation in the cat caused increased 5-HT levels in the portal plasma to more than twice the normal values after 15 min stimulation. Administration of the beta-adrenoceptor antagonist d, 1-propranolol in various doses did not abolish, but significantly reduced the response, particularly during the final part of the stimulation period. These results not only confirm a beta-adrenoceptor mediated release of 5-HT, but also suggest that other mechanisms are involved in the total response to vagal nerve stimulation.

UI	MeSH Term	Description	Entries
D007413	Intestinal Mucosa	Lining of the INTESTINES, consisting of an inner EPITHELIUM, a middle LAMINA PROPRIA, and an outer MUSCULARIS MUCOSAE. In the SMALL INTESTINE, the mucosa is characterized by a series of folds and abundance of absorptive cells (ENTEROCYTES) with MICROVILLI.	Intestinal Epithelium,Intestinal Glands,Epithelium, Intestinal,Gland, Intestinal,Glands, Intestinal,Intestinal Gland,Mucosa, Intestinal
D008297	Male		Males
D009638	Norepinephrine	Precursor of epinephrine that is secreted by the ADRENAL MEDULLA and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers, and of the diffuse projection system in the brain that arises from the LOCUS CERULEUS. It is also found in plants and is used pharmacologically as a sympathomimetic.	Levarterenol,Levonorepinephrine,Noradrenaline,Arterenol,Levonor,Levophed,Levophed Bitartrate,Noradrenaline Bitartrate,Noradrénaline tartrate renaudin,Norepinephrin d-Tartrate (1:1),Norepinephrine Bitartrate,Norepinephrine Hydrochloride,Norepinephrine Hydrochloride, (+)-Isomer,Norepinephrine Hydrochloride, (+,-)-Isomer,Norepinephrine d-Tartrate (1:1),Norepinephrine l-Tartrate (1:1),Norepinephrine l-Tartrate (1:1), (+,-)-Isomer,Norepinephrine l-Tartrate (1:1), Monohydrate,Norepinephrine l-Tartrate (1:1), Monohydrate, (+)-Isomer,Norepinephrine l-Tartrate (1:2),Norepinephrine l-Tartrate, (+)-Isomer,Norepinephrine, (+)-Isomer,Norepinephrine, (+,-)-Isomer
D011433	Propranolol	A widely used non-cardioselective beta-adrenergic antagonist. Propranolol has been used for MYOCARDIAL INFARCTION; ARRHYTHMIA; ANGINA PECTORIS; HYPERTENSION; HYPERTHYROIDISM; MIGRAINE; PHEOCHROMOCYTOMA; and ANXIETY but adverse effects instigate replacement by newer drugs.	Dexpropranolol,AY-20694,Anaprilin,Anapriline,Avlocardyl,Betadren,Dociton,Inderal,Obsidan,Obzidan,Propanolol,Propranolol Hydrochloride,Rexigen,AY 20694,AY20694,Hydrochloride, Propranolol
D011941	Receptors, Adrenergic	Cell-surface proteins that bind epinephrine and/or norepinephrine with high affinity and trigger intracellular changes. The two major classes of adrenergic receptors, alpha and beta, were originally discriminated based on their cellular actions but now are distinguished by their relative affinity for characteristic synthetic ligands. Adrenergic receptors may also be classified according to the subtypes of G-proteins with which they bind; this scheme does not respect the alpha-beta distinction.	Adrenergic Receptors,Adrenoceptor,Adrenoceptors,Norepinephrine Receptor,Receptors, Epinephrine,Receptors, Norepinephrine,Adrenergic Receptor,Epinephrine Receptors,Norepinephrine Receptors,Receptor, Adrenergic,Receptor, Norepinephrine
D011943	Receptors, Adrenergic, beta	One of two major pharmacologically defined classes of adrenergic receptors. The beta adrenergic receptors play an important role in regulating CARDIAC MUSCLE contraction, SMOOTH MUSCLE relaxation, and GLYCOGENOLYSIS.	Adrenergic beta-Receptor,Adrenergic beta-Receptors,Receptors, beta-Adrenergic,beta Adrenergic Receptor,beta-Adrenergic Receptor,beta-Adrenergic Receptors,Receptor, Adrenergic, beta,Adrenergic Receptor, beta,Adrenergic beta Receptor,Adrenergic beta Receptors,Receptor, beta Adrenergic,Receptor, beta-Adrenergic,Receptors, beta Adrenergic,beta Adrenergic Receptors,beta-Receptor, Adrenergic,beta-Receptors, Adrenergic
D002838	Chromaffin System	The cells of the body which stain with chromium salts. They occur along the sympathetic nerves, in the adrenal gland, and in various other organs.	Argentaffin System,Argentaffin Systems,Chromaffin Systems,System, Argentaffin,System, Chromaffin,Systems, Argentaffin,Systems, Chromaffin
D004386	Duodenum	The shortest and widest portion of the SMALL INTESTINE adjacent to the PYLORUS of the STOMACH. It is named for having the length equal to about the width of 12 fingers.	Duodenums
D004558	Electric Stimulation	Use of electric potential or currents to elicit biological responses.	Stimulation, Electric,Electrical Stimulation,Electric Stimulations,Electrical Stimulations,Stimulation, Electrical,Stimulations, Electric,Stimulations, Electrical
D004759	Enterochromaffin Cells	A subtype of enteroendocrine cells found in the gastrointestinal MUCOSA, particularly in the glands of PYLORIC ANTRUM; DUODENUM; and ILEUM. These cells secrete mainly SEROTONIN and some neuropeptides. Their secretory granules stain readily with silver (argentaffin stain).	Argentaffin Cells,5-HT-Containing Enterochromaffin Cells,Serotonin-Containing Enterochromaffin Cells,5 HT Containing Enterochromaffin Cells,5-HT-Containing Enterochromaffin Cell,Argentaffin Cell,Cell, Enterochromaffin,Cells, Enterochromaffin,Enterochromaffin Cell,Enterochromaffin Cell, 5-HT-Containing,Enterochromaffin Cell, Serotonin-Containing,Enterochromaffin Cells, 5-HT-Containing,Enterochromaffin Cells, Serotonin-Containing,Serotonin Containing Enterochromaffin Cells,Serotonin-Containing Enterochromaffin Cell