Effects of stress and. beta. -funal trexamine pretreatment on morphine analgesia and opioid binding in rats

Journal Article · Mon Dec 28 04:00:00 EST 1987 · Life Sci.; (United States)

DOI:https://doi.org/10.1016/0024-3205(87)90430-9· OSTI ID:5653895

Adams, J U; Andrews, J S; Hiller, J M; Simon, E J; Holtzman, S G

This study was essentially an in vivo protection experiment designed to test further the hypothesis that stress induces release of endogenous opiods which then act at opioid receptors. Rats that were either subjected to restraint stress for 1 yr or unstressed were injected ICV with either saline or 2.5 ..mu..g of ..beta..-funaltrexamine (..beta..-FNA), an irreversible opioid antagonist that alkylates the mu-opioid receptor. Twenty-four hours later, subjects were tested unstressed for morphine analgesia or were sacrificed and opioid binding in brain was determined. (/sup 3/H)D-Ala/sup 2/NMePhe/sup 4/-Gly/sup 5/(ol)enkephalin (DAGO) served as a specific ligand for mu-opioid receptors, and (/sup 3/H)-bremazocine as a general ligand for all opioid receptors. Rats injected with saline while stressed were significantly less sensitive to the analgesic action of morphine 24 hr later than were their unstressed counterparts. ..beta..-FNA pretreatment attenuated morphine analgesia in an insurmountable manner. Animals pretreated with ..beta..-FNA while stressed were significantly more sensitive to the analgesic effect of morphine than were animals that received ..beta..-FNA while unstressed. ..beta..-FNA caused small and similar decreases in (/sup 3/H)-DAGO binding in brain of both stressed and unstressed animals. 35 references, 2 figures, 2 tables.

• Research Organization: Emory Univ. School of Medicine, Atlanta, GA
• OSTI ID: 5653895
• Journal Information: Life Sci.; (United States), Journal Name: Life Sci.; (United States) Vol. 41:26; ISSN LIFSA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALOIDS
ANALGESICS
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL EFFECTS
BIOLOGICAL STRESS
CENTRAL NERVOUS SYSTEM DEPRESSANTS
DRUGS
ENDORPHINS
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LIGANDS
MAMMALS
MEMBRANE PROTEINS
MORPHINE
NARCOTICS
NEUROREGULATORS
OPIUM
ORGANIC COMPOUNDS
PROTEINS
RATS
REACTION KINETICS
RECEPTORS
RESPONSE MODIFYING FACTORS
RODENTS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES