FMRFamide is a molluscan peptide that has shown antiopiate activity in a number of mammalian test systems. The current study determined the antiopiate potency of FMRFamide and two conformationally constrained peptidomimetics of FMRFamide containing stereoisomers of (E)-2,3-methanomethionine. Morphine abstinence signs were observed after varying doses (0.25-25.0 microgram) of these substances were injected into the third ventricle of morphine-dependent rats. Both peptidomimetics were far more potent than FMRFamide itself. In addition, although both peptidomimetics bound with lower affinity than FMRFamide to rat spinal cord receptors for NPFF (the mammalian FMRFamide-like peptide), they were far more resistant than FMRFamide to enzymatic degradation by leucine aminopeptidase.

Download full-text PDF

Source
http://dx.doi.org/10.1016/0196-9781(93)90105-pDOI Listing

Publication Analysis

Top Keywords

antiopiate activity
8
peptidomimetics fmrfamide
8
fmrfamide
7
enhanced antiopiate
4
activity enzyme
4
enzyme resistance
4
peptidomimetics
4
resistance peptidomimetics
4
fmrfamide e-23-methanomethionine
4
e-23-methanomethionine fmrfamide
4

Similar Publications

DARK Classics in Chemical Neuroscience: Ibogaine.

ACS Chem Neurosci

October 2018

Arnold & Marie Schwartz College of Pharmacy and Health Sciences , Long Island University-Brooklyn, 75 DeKalb Avenue , Brooklyn , New York 11201 , United States.

The West African iboga plant has been used for centuries by the Bwiti and Mbiri tribes to induce hallucinations during religious ceremonies. Ibogaine, the principal alkaloid responsible for iboga's psychedelic properties, was isolated and sold as an antidepressant in France for decades before its adverse effects precipitated its removal from the market. An ibogaine resurgence in the 1960s was driven by U.

View Article and Find Full Text PDF

Considerable evidence suggests the Neuropeptide FF (NPFF) and related peptides exert pro-nociceptive and anti-opiate actions, particularly at the supra-spinal level, which may contribute to opiate dependence. The FF1 receptor subtype appears to be primarily responsible for anti-opiate effects. In contrast, stimulation of the FF2 receptor primarily induces pro-opiate effects.

View Article and Find Full Text PDF

The neuronal circuit between nociceptin/orphanin FQ and hypocretins/orexins coordinately modulates stress-induced analgesia and anxiety-related behavior.

Vitam Horm

September 2015

AfaSci Research Laboratories, Redwood City, California, USA; Department of Anesthesia, Stanford University School of Medicine, Stanford, California, USA. Electronic address:

The neuropeptide nociceptin/orphanin FQ (N/OFQ), acting on its receptors (NOP), modulates a variety of biological functions and neurobehavior including nociception, stress responses, water and food-intake, locomotor activity, and spatial attention. N/OFQ is conventionally regarded as an "antiopiate" peptide in the brain because central administration of N/OFQ attenuates stress-induced analgesia (SIA) and produces anxiolytic effects. However, naloxone-irreversible SIA and anxiolytic action are unlikely to be mediated by the opiate system.

View Article and Find Full Text PDF

Concepts for biologically active peptides.

Curr Pharm Des

October 2010

Blood-Brain Barrier Group, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA.

Here we review a unique aspect of CNS research on biologically active peptides that started against a background of prevalent dogmas but ended by exerting considerable influence on the field. During the course of refuting some doctrines, we introduced several concepts that were unconventional and paradigm-shifting at the time. We showed that (1) hypothalamic peptides can act 'up' on the brain as well as 'down' on the pituitary, (2) peripheral peptides can affect the brain, (3) peptides can cross the blood-brain barrier, (4) the actions of peptides can persist longer than their half-lives in blood, (5) perinatal administration of peptides can exert actions persisting into adulthood, (6) a single peptide can have more than one action, (7) dose-response relationships of peptides need not be linear, (8) the brain produces antiopiate as well as opiate peptides, (9) there is a selective high affinity endogenous peptide ligand for the mu-opiate receptor, (10) a peptide's name does not restrict its effects, and (11) astrocytes assume an active role in response to metabolic disturbance and hyperleptinemia.

View Article and Find Full Text PDF

From MIF-1 to endomorphin: the Tyr-MIF-1 family of peptides.

Peptides

December 2007

Blood-Brain Barrier Group, Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA 70808, USA.

The Tyr-MIF-1 family of small peptides has served a prototypic role in the introduction of several novel concepts into the peptide field of research. MIF-1 (Pro-Leu-Gly-NH(2)) was the first hypothalamic peptide shown to act "up" on the brain, not just "down" on the pituitary. In several situations, including clinical depression, MIF-1 exhibits an inverted U-shaped dose-response relationship in which increasing doses can result in decreasing effects.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!