Dietary Glutamate: Interactions With the Enteric Nervous System
| Autor: | Jackie D Wood, Yun Xia, Guo-Du Wang, Xi-Yu Wang |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
Agonist
medicine.medical_specialty Pathology medicine.drug_class Secretomotor Biology 03 medical and health sciences chemistry.chemical_compound Glutamatergic 0302 clinical medicine Internal medicine medicine Myenteric plexus Secretion 030304 developmental biology 0303 health sciences Receptors glutamate Gastroenterology Glutamate receptor Motility Intestines Endocrinology Metabotropic receptor chemistry Proteolysis ACPD Enteric nervous system Original Article Neurology (clinical) 030217 neurology & neurosurgery |
| Zdroj: | Journal of Neurogastroenterology and Motility |
| ISSN: | 2093-0887 2093-0879 |
| Popis: | Background/Aims Digestion of dietary protein elevates intraluminal concentrations of glutamate in the small intestine, some of which gain access to the enteric nervous system (ENS). Glutamate, in the central nervous system (CNS), is an excitatory neurotransmitter. A dogma that glutamatergic neurophysiology in the ENS recapitulates CNS glutamatergic function persists. We reassessed the premise that glutamatergic signaling in the ENS recapitulates its neurotransmitter role in the CNS. Methods Pharmacological analysis of actions of receptor agonists and antagonists in concert with immunohistochemical localization of glutamate transporters and receptors was used. Analysis focused on intracellularly-recorded electrical and synaptic behavior of ENS neurons, on stimulation of mucosal secretion by secretomotor neurons in the submucosal plexus and on muscle contractile behavior mediated by musculomotor neurons in the myenteric plexus. Results Immunoreactivity for glutamate was expressed in ENS neurons. ENS neurons expressed immunoreactivity for the EAAC-1 glutamate transporter. Neither L-glutamate nor glutamatergic receptor agonists had excitatory actions on ENS neurons. Metabotropic glutamatergic receptor agonists did not directly stimulate neurogenic mucosal chloride secretion. Neither L-glutamate nor the metabotropic glutamatergic receptor agonist, aminocyclopentane-1,3-dicarboxylic acid (ACPD), changed the mean amplitude of spontaneously occurring contractions in circular or longitudinal strips of intestinal wall from either guinea pig or human small intestinal preparations. Conclusions Early discoveries, for excitatory glutamatergic neurotransmission in the CNS, inspired enthusiasm that investigation in the ENS would yield discoveries recapitulating the CNS glutamatergic story. We found this not to be the case. |
| Databáze: | OpenAIRE |
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