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Modulation of neurotransmitter release by opioid mu- and kappa-receptors from adrenergic terminals in the myenteric plexus of the guinea-pig colon: effect of alpha 2-autoreceptor blockade.
- Source :
-
Neuroscience letters [Neurosci Lett] 1997 Jan 31; Vol. 222 (2), pp. 75-8. - Publication Year :
- 1997
-
Abstract
- We have studied the effect of [D-Ala2,N-Me-Phe4,Gly-ol5]-enkephalin (DAMGO, opioid mu-receptor agonist) and ICI-204,448 (kappa-receptor agonist) on endogenous noradrenaline release in the guinea-pig isolated distal colon. DAMGO enhances noradrenaline over-flow and this effect is antagonized by naloxone (pIC50 = 10.27) and nor-binaltorphimine (pIC50 = 7.97), and concentration-dependently turned into inhibition by yohimbine. ICI-204,448 inhibits noradrenaline overflow and is antagonized by naloxone (pIC50 = 9.38) and nor-binaltorphimine (pIC50 = 10.48), but is not affected by yohimbine. Evidence is thus given that mu- and kappa-opioid receptors modulate noradrenaline release in the guinea-pig colon. Modifications by yohimbine of the effect of DAMGO indicate the existence of a functional relationship between mu-receptors and alpha(2)-autoreceptors in this model.
- Subjects :
- Adrenergic alpha-2 Receptor Antagonists
Adrenergic alpha-Agonists metabolism
Adrenergic alpha-Agonists pharmacology
Analgesics pharmacology
Animals
Colon innervation
Dose-Response Relationship, Drug
Electric Stimulation
Enkephalin, Ala(2)-MePhe(4)-Gly(5)-
Enkephalins pharmacology
Guinea Pigs
Myenteric Plexus drug effects
Myenteric Plexus metabolism
Naloxone pharmacology
Naltrexone analogs & derivatives
Naltrexone pharmacology
Narcotic Antagonists pharmacology
Neurotransmitter Agents metabolism
Norepinephrine metabolism
Norepinephrine pharmacology
Pyrrolidines pharmacology
Receptors, Opioid, kappa agonists
Receptors, Opioid, kappa antagonists & inhibitors
Receptors, Opioid, mu agonists
Receptors, Opioid, mu antagonists & inhibitors
Yohimbine pharmacology
Adrenergic alpha-Antagonists pharmacology
Myenteric Plexus chemistry
Receptors, Adrenergic, alpha-2 metabolism
Receptors, Opioid, kappa metabolism
Receptors, Opioid, mu metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0304-3940
- Volume :
- 222
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Neuroscience letters
- Publication Type :
- Academic Journal
- Accession number :
- 9111732
- Full Text :
- https://doi.org/10.1016/s0304-3940(97)13344-4