Mice subjected to defeat in a social conflict paradigm display an analgesic response that is apparently mediated by endogenous opioids. It is blocked by naloxone and shows full cross-tolerance to and from morphine. The present study investigated the contribution of sources of endogenous opioids outside of the central nervous system, namely the pituitary and adrenal glands. Treatment known to enhance (metyrapone pretreatment), reduce (2% saline in the drinking water) or block (dexamethasone pretreatment) the release of beta-endorphin from the anterior pituitary did not affect the display of analgesia in defeated mice. Similarly, treatments known to enhance (reserpine pretreatment) or block release of enkephalins (removal of the adrenals or hexamethonium pretreatment) from the adrenal medulla also failed to influence defeat-induced analgesia in the expected manner. If anything, adrenalectomy enhanced and reserpine pretreatment suppressed the analgesic response to defeat. The data are discussed in terms of providing evidence that defeat-induced analgesia is mediated primarily by endogenous opioids released and acting within the central nervous system.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/0091-3057(88)90002-0 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Musicians and researchers: two creative professions striving to improve heart health through music.
Front Cardiovasc Med
January 2025
Institute of Molecular Pathobiochemistry, Experimental Gene Therapy and Clinical Chemistry (IFMPEGKC), RWTH University Hospital Aachen, Aachen, Germany.
Musicians and researchers are creative professions that share many similarities. They both aim to bring joy and progress to humanity. In recent decades, it has been shown that music has the ability to alleviate pain, improve heart function, reduce anxiety, and stimulate the release of endogenous opioids in the brain.
View Article and Find Full Text PDFPhytochemical profile of Taxus globosa Schltdl. and its anxiolytic, antinociceptive, and toxicological evaluation in mice.
J Ethnopharmacol
January 2025
Posgrado en Botánica, Colegio Postgraduados Campus Montecillo Km. 36.5 Carretera México-Texcoco C.P. Montecillo, 56264, Texcoco Estado de México, México. Electronic address:
Ethnopharmacological Relevance: Taxus globosa Schltdl. (Taxaceae) is commonly named "Tejo mexicano". It's a Mexican plant known in folk medicine as a remedy for pain such as stomachache and headache, arthritis, gout, and other inflammatory conditions.
View Article and Find Full Text PDFThe Role of Endogenous Beta-Endorphin and Enkephalins in the Crosstalk Between Ethanol and Morphine.
Pharmaceuticals (Basel)
January 2025
Department of Biotechnology and Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, CA 91766, USA.
There is clinical concern about the combined use of alcohol and opiates. Several lines of evidence support an interaction between alcohol and the endogenous opioid system. Thus, we hypothesized that ethanol, by causing the release of opioid peptides, may sensitize the system to the action of exogenous opioids such as morphine.
View Article and Find Full Text PDFA Comprehensive Analysis of Fibromyalgia and the Role of the Endogenous Opioid System.
Biomedicines
January 2025
Program of Immunology and Immunotherapy, CIMA-Universidad de Navarra, 31008 Pamplona, Spain.
Fibromyalgia represents a chronic pain disorder characterized by musculoskeletal pain, fatigue, and cognitive impairments. The exact mechanisms underlying fibromyalgia remain undefined; as a result, diagnosis and treatment present considerable challenges. On the other hand, the endogenous opioid system is believed to regulate pain intensity and emotional responses; hence, it might be expected to play a key role in the enhanced sensitivity experienced by fibromyalgia patients.
View Article and Find Full Text PDFImpact of β-casein variants on the formation of β-casomorphins in blue cheeses: Investigating key drivers through peptidomic analysis.
Food Res Int
February 2025
Department of Agriculture, University of Naples "Federico II", 80055 Portici, Italy.
β-Casomorphins (BCMs), food-associated peptides resulting from the proteolytic cleavage of β-casein (β-CN), have been widely investigated for their opioid-like activity. This research aimed to identify the presence of BCM7, BCM6, and BCM5 in different bovine milk-deriving blue cheese types and to describe the intricate mechanisms behind their formation, focusing on their origin from cheese with β-CN A1 and A2 variants. Using nanoLC-ESI-Q-Orbitrap-MS/MS and advanced computational tools, we explored the peptidomes of Bleu d'Auvergne, Gorgonzola, Stilton, and Bergader blue cheeses from milk containing both β-CN A1 and A2 variants.
View Article and Find Full Text PDFWant 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!