Biomaterial Database

Opioid-receptor-mediated excitation of rat mesenteric afferent fibres supplying the rat jejunum. 2000

C Eastwood, and D Grundy

Department of Biomedical Science, University of Sheffield, UK.

The aim of the present study was to examine the sensitivity to opioid-receptor agonists of mesenteric afferents supplying the small intestine and to characterize the subpopulations of any responsive fibres. Mesenteric afferent discharge was recorded electrophysiologically in response to cumulative doses (1-400 microgram kg-1) of the mu-receptor agonist [D-ala,2 N- me-Phe4, Gly5-ol]-enkephalin (DAMGO), the delta-receptor agonist [D-ala,2 D-leu5]-enkephalin (DADLE) and the kappa-receptor agonist U-50488. DAMGO and DADLE, but not U-50488, markedly stimulated whole nerve mesenteric afferent discharge (P < 0.05) that was unrelated to intestinal motor events. Subpopulations of afferent fibres responding to DAMGO were examined using waveform analysis to identify single units from within the whole mesenteric nerve bundles. One population was CCK-sensitive (15/15 fibres) and the other was a subpopulation of mechanosensitive afferents that responded to distension (17/28). 5-HT-sensitive afferents did not respond to DAMGO (0/11). We conclude that specific subpopulations of mesenteric afferents respond to mu- and possibly delta- but not kappa-receptor agonists. This sensitivity to opioids may contribute to the antinociceptive property of vagal afferents.

UI	MeSH Term	Description	Entries
D007583	Jejunum	The middle portion of the SMALL INTESTINE, between DUODENUM and ILEUM. It represents about 2/5 of the remaining portion of the small intestine below duodenum.	Jejunums
D008297	Male		Males
D009475	Neurons, Afferent	Neurons which conduct NERVE IMPULSES to the CENTRAL NERVOUS SYSTEM.	Afferent Neurons,Afferent Neuron,Neuron, Afferent
D011957	Receptors, Opioid	Cell membrane proteins that bind opioids and trigger intracellular changes which influence the behavior of cells. The endogenous ligands for opioid receptors in mammals include three families of peptides, the enkephalins, endorphins, and dynorphins. The receptor classes include mu, delta, and kappa receptors. Sigma receptors bind several psychoactive substances, including certain opioids, but their endogenous ligands are not known.	Endorphin Receptors,Enkephalin Receptors,Narcotic Receptors,Opioid Receptors,Receptors, Endorphin,Receptors, Enkephalin,Receptors, Narcotic,Receptors, Opiate,Endorphin Receptor,Enkephalin Receptor,Normorphine Receptors,Opiate Receptor,Opiate Receptors,Opioid Receptor,Receptors, Normorphine,Receptors, beta-Endorphin,beta-Endorphin Receptor,Receptor, Endorphin,Receptor, Enkephalin,Receptor, Opiate,Receptor, Opioid,Receptor, beta-Endorphin,Receptors, beta Endorphin,beta Endorphin Receptor,beta-Endorphin Receptors
D004305	Dose-Response Relationship, Drug	The relationship between the dose of an administered drug and the response of the organism to the drug.	Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
D000701	Analgesics, Opioid	Compounds with activity like OPIATE ALKALOIDS, acting at OPIOID RECEPTORS. Properties include induction of ANALGESIA or NARCOSIS.	Opioid,Opioid Analgesic,Opioid Analgesics,Opioids,Full Opioid Agonists,Opioid Full Agonists,Opioid Mixed Agonist-Antagonists,Opioid Partial Agonists,Partial Opioid Agonists,Agonist-Antagonists, Opioid Mixed,Agonists, Full Opioid,Agonists, Opioid Full,Agonists, Opioid Partial,Agonists, Partial Opioid,Analgesic, Opioid,Full Agonists, Opioid,Mixed Agonist-Antagonists, Opioid,Opioid Agonists, Full,Opioid Agonists, Partial,Opioid Mixed Agonist Antagonists,Partial Agonists, Opioid
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D014628	Vagotomy	The interruption or removal of any part of the vagus (10th cranial) nerve. Vagotomy may be performed for research or for therapeutic purposes.	Vagotomies
D014630	Vagus Nerve	The 10th cranial nerve. The vagus is a mixed nerve which contains somatic afferents (from skin in back of the ear and the external auditory meatus), visceral afferents (from the pharynx, larynx, thorax, and abdomen), parasympathetic efferents (to the thorax and abdomen), and efferents to striated muscle (of the larynx and pharynx).	Cranial Nerve X,Pneumogastric Nerve,Tenth Cranial Nerve,Nerve X,Nervus Vagus,Cranial Nerve, Tenth,Cranial Nerves, Tenth,Nerve X, Cranial,Nerve Xs,Nerve, Pneumogastric,Nerve, Tenth Cranial,Nerve, Vagus,Nerves, Pneumogastric,Nerves, Tenth Cranial,Nerves, Vagus,Pneumogastric Nerves,Tenth Cranial Nerves,Vagus Nerves,Vagus, Nervus
D016308	Enkephalin, Leucine-2-Alanine	A delta-selective opioid (ANALGESICS, OPIOID). It can cause transient depression of mean arterial blood pressure and heart rate.	2-Alanyl-Leucine Enkephalin,5-Leucine-2-Alanine Enkephalin,D-Ala(2)-D-Leu(5)-Enkephalin,Enkephalin-Leu,Ala(2),Leucine Enkephalin-2-Alanine,BW-180C,DADLE,Leu-Enkephalin-2-Ala,2 Alanyl Leucine Enkephalin,5 Leucine 2 Alanine Enkephalin,BW 180C,BW180C,Enkephalin, 2-Alanyl-Leucine,Enkephalin, 5-Leucine-2-Alanine,Enkephalin, Leucine 2 Alanine,Enkephalin-2-Alanine, Leucine,Leu Enkephalin 2 Ala,Leucine Enkephalin 2 Alanine,Leucine-2-Alanine Enkephalin