Biomaterial Database

Effects of naloxone and opioid agonists on gastric excitatory responses to stimulation of the vagus nerve in cats. 1988

T Okamoto, and K Kurahashi, and M Fujiwara

Department of Pharmacology, Faculty of Medicine, Kyoto University, Japan.

1. An investigation was made into the contribution of endogenous opioids to the initial and delayed excitatory response of the stomach induced by stimulation of the vagal trunk in cats. 2. Naloxone (100 to 1000 micrograms kg-1) had no effect on the initial excitatory response to stimulation of the vagal efferent fibres. However, the same treatment dose-dependently enhanced the delayed excitatory response to stimulation of the vagal afferent fibres. 3. In comparison with the mu-opioid-receptor agonist, [D-Ala2, MePhe4, Gly-ol5]enkephalin and the kappa-opioid-receptor agonist dynorphin A (1-13), lower doses of methionine enkephalin [( Met]enkephalin) markedly inhibited the excitation caused by stimulation of the vagal efferent and afferent fibres. The inhibitory effect of [Met]enkephalin was antagonized by naloxone. 4. The delta-opioid-receptor selective agonist [D-Pen2, D-Pen5]enkephalin mimicked the inhibitory effects of [Met]enkephalin and inhibition by [D-Pen2, D-Pen5]enkephalin was antagonized by the delta-opioid-receptor antagonist, ICI 174,864. 5. It is concluded that the inhibitory effects of exogenous opioids on the excitatory response of the stomach to stimulation of the vagal efferent and afferent fibres are mediated, at least in part, by delta-opioid-receptors. Naturally occurring opioids may participate in the inhibition of the delayed gastric excitation to stimulation of the vagal afferent fibres.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009270	Naloxone	A specific opiate antagonist that has no agonist activity. It is a competitive antagonist at mu, delta, and kappa opioid receptors.	MRZ 2593-Br,MRZ-2593,Nalone,Naloxon Curamed,Naloxon-Ratiopharm,Naloxone Abello,Naloxone Hydrobromide,Naloxone Hydrochloride,Naloxone Hydrochloride Dihydride,Naloxone Hydrochloride, (5 beta,9 alpha,13 alpha,14 alpha)-Isomer,Naloxone, (5 beta,9 alpha,13 alpha,14 alpha)-Isomer,Narcan,Narcanti,Abello, Naloxone,Curamed, Naloxon,Dihydride, Naloxone Hydrochloride,Hydrobromide, Naloxone,Hydrochloride Dihydride, Naloxone,Hydrochloride, Naloxone,MRZ 2593,MRZ 2593 Br,MRZ 2593Br,MRZ2593,Naloxon Ratiopharm
D009292	Narcotic Antagonists	Agents inhibiting the effect of narcotics on the central nervous system.	Competitive Opioid Antagonist,Narcotic Antagonist,Opioid Antagonist,Opioid Antagonists,Opioid Receptor Antagonist,Opioid Reversal Agent,Competitive Opioid Antagonists,Opioid Receptor Antagonists,Opioid Reversal Agents,Agent, Opioid Reversal,Agents, Opioid Reversal,Antagonist, Competitive Opioid,Antagonist, Narcotic,Antagonist, Opioid,Antagonist, Opioid Receptor,Antagonists, Competitive Opioid,Antagonists, Narcotic,Antagonists, Opioid,Antagonists, Opioid Receptor,Opioid Antagonist, Competitive,Opioid Antagonists, Competitive,Receptor Antagonist, Opioid,Receptor Antagonists, Opioid,Reversal Agent, Opioid,Reversal Agents, Opioid
D009294	Narcotics	Agents that induce NARCOSIS. Narcotics include agents that cause somnolence or induced sleep (STUPOR); natural or synthetic derivatives of OPIUM or MORPHINE or any substance that has such effects. They are potent inducers of ANALGESIA and OPIOID-RELATED DISORDERS.	Analgesics, Narcotic,Narcotic Analgesics,Narcotic,Narcotic Effect,Narcotic Effects,Effect, Narcotic,Effects, Narcotic
D010446	Peptide Fragments	Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.	Peptide Fragment,Fragment, Peptide,Fragments, Peptide
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D004399	Dynorphins	A class of opioid peptides including dynorphin A, dynorphin B, and smaller fragments of these peptides. Dynorphins prefer kappa-opioid receptors (RECEPTORS, OPIOID, KAPPA) and have been shown to play a role as central nervous system transmitters.	Dynorphin,Dynorphin (1-17),Dynorphin A,Dynorphin A (1-17)
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
D004723	Endorphins	One of the three major groups of endogenous opioid peptides. They are large peptides derived from the PRO-OPIOMELANOCORTIN precursor. The known members of this group are alpha-, beta-, and gamma-endorphin. The term endorphin is also sometimes used to refer to all opioid peptides, but the narrower sense is used here; OPIOID PEPTIDES is used for the broader group.	Endorphin
D004743	Enkephalin, Leucine	One of the endogenous pentapeptides with morphine-like activity. It differs from MET-ENKEPHALIN in the LEUCINE at position 5. Its first four amino acid sequence is identical to the tetrapeptide sequence at the N-terminal of BETA-ENDORPHIN.	Leucine Enkephalin,5-Leucine Enkephalin,Leu(5)-Enkephalin,Leu-Enkephalin,5 Leucine Enkephalin,Enkephalin, 5-Leucine,Leu Enkephalin