Peptide displacement of ( sup 3 H)5-hydroxytryptamine binding to bovine cortical membranes

Journal Article · Sat Dec 01 00:00:00 EST 1990 · Brain Research Bulletin; (USA)

DOI:https://doi.org/10.1016/0361-9230(90)90176-Z· OSTI ID:5947104

Takeuchi, Y; Root-Bernstein, R S; Shih, J C ^[1]

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1. Samuel Roberts Noble Foundation, Inc., Ardmore, OK (USA)

Chemical studies have demonstrated that peptides such as the encephalitogenic (EAE) peptide of myelin basic protein (MBP) and luteinizing hormone-releasing hormone (LHRH) can bind serotonin (5-hydroxytryptamine, 5-HT) in vitro. The present research was undertaken to determine whether such binding interferes with 5-HT binding to its 5-HT1 receptors on bovine cerebral cortical membranes. EAE peptide and LHRH displaced ({sup 3}H)5-HT with IC50s of 4.0 x 10(-4) and 1.8 x 10(-3) M respectively. MBP itself also showed apparent displacing ability with an IC50 of 6.0 x 10(-5) M, though it also caused aggregation of cortical membranes that might have interfered with normal receptor binding. These results support previous suggestions that the tryptophan peptide region of MBP may act as a 5-HT receptor in the neural system. We also tested the effects of muramyl dipeptide (N-acetyl-muramyl-L-Ala-D-isoGln, MD), a bacterial cell-wall breakdown product that acts as a slow-wave sleep promoter, binds to LHRH and EAE peptide, and competes for 5-HT binding sites on macrophages. It showed no significant displacement of 5-HT binding to cortical membranes (IC50 greater than 10(-1) M), but its D-Ala analogue did (IC50 = 1.7 x 10(-3) M). Thus, it seems likely that the 5-HT-related effects of naturally occurring muramyl peptides are physiologically limited by receptor types.

• OSTI ID: 5947104
• Journal Information: Brain Research Bulletin; (USA), Vol. 25:6; ISSN 0361-9230
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
PEPTIDES
BIOLOGICAL FUNCTIONS
SEROTONIN
BIOCHEMICAL REACTION KINETICS
CATTLE
CELL MEMBRANES
CEREBRAL CORTEX
MACROPHAGES
RECEPTORS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
AMINES
ANIMAL CELLS
ANIMALS
AROMATICS
AUTONOMIC NERVOUS SYSTEM AGENTS
AZAARENES
AZOLES
BODY
BRAIN
CELL CONSTITUENTS
CENTRAL NERVOUS SYSTEM
CEREBRUM
CONNECTIVE TISSUE CELLS
DOMESTIC ANIMALS
DRUGS
FUNCTIONS
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
INDOLES
ISOTOPE APPLICATIONS
KINETICS
MAMMALS
MEMBRANE PROTEINS
MEMBRANES
NERVOUS SYSTEM
NEUROREGULATORS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PHAGOCYTES
PROTEINS
PYRROLES
RADIOPROTECTIVE SUBSTANCES
REACTION KINETICS
RUMINANTS
SOMATIC CELLS
SYMPATHOMIMETICS
TRYPTAMINES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques