Stereospecific transport of Tyr-MIF-1 across the blood-brain barrier by peptide transport system-1

Journal Article · Mon Oct 01 00:00:00 EDT 1990 · Brain Research Bulletin; (USA)

DOI:https://doi.org/10.1016/0361-9230(90)90116-H· OSTI ID:6010245

Banks, W A; Kastin, A J; Michals, E A; Barrera, C M ^[1]

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1. Veterans Affairs Medical Center, New Orleans, LA (USA)

Previous studies have suggested that peptide transport system-1 (PTS-1), the saturable system that transports Tyr-MIF-1, the enkephalins, and related peptides out of the central nervous system (CNS), exhibits stereospecificity. In the present studies, we showed that {sup 125}I-L-Tyr-MIF-1, but not {sup 131}I-D-Tyr-MIF-1, was cleared from the CNS more rapidly than could be accounted for by nonspecific mechanisms. Such clearance was inhibited by a 1.0 nmol dose of L-Tyr-MIF-1, but not by D-Tyr-MIF-1. Neither L- nor D-Tyr-MIF-1 altered the much lower clearance of I-D-Tyr-MIF-1 from the brain. Radioactivity recovered from the vascular space after the injection of {sup 125}I-Tyr-MIF-1 into the lateral ventricle of the brain eluted by HPLC primarily as intact peptide, demonstrating that most of the Tyr-MIF-1 was not degraded during transport. By contrast, the nonsaturable unidirectional influx of Tyr-MIF-1 into the CNS did not distinguish between the isomers. These studies confirm and extend the observations that Tyr-MIF-1 is transported out of the CNS by a saturable, stereospecific transport system as an intact peptide while the influx into the CNS is by a nonsaturable mechanism that does not distinguish between the isomers.

• OSTI ID: 6010245
• Journal Information: Brain Research Bulletin; (USA), Vol. 25:4; ISSN 0361-9230
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
BLOOD-BRAIN BARRIER
PERMEABILITY
ENKEPHALINS
MEMBRANE TRANSPORT
BRAIN
CLEARANCE
IODINE 125
IODINE 131
LIQUID COLUMN CHROMATOGRAPHY
MICE
PEPTIDES
RATS
TRACER TECHNIQUES
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CENTRAL NERVOUS SYSTEM
CHROMATOGRAPHY
DAYS LIVING RADIOISOTOPES
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
ENDORPHINS
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
MAMMALS
NERVOUS SYSTEM
NEUROREGULATORS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
POLYPEPTIDES
PROTEINS
RADIOISOTOPES
RODENTS
SEPARATION PROCESSES
VERTEBRATES
550501* - Metabolism- Tracer Techniques