sup 125 I-(Tyr0,D-Trp8)somatostatin-14 binding sites in the locus coeruleus of the rat are located on both ascending and descending projecting noradrenergic cells

Journal Article · Mon Jan 01 04:00:00 EST 1990 · Peptides (Fayetteville, New York); (USA)

DOI:https://doi.org/10.1016/0196-9781(90)90104-D· OSTI ID:7016221

Epelbaum, J; Bluet-Pajot, M T; Llorens-Cortes, C; Kordon, C; Mounier, F; Senut, M C; Videau, C ^[1]

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1. U159 INSERM, Paris (France)

Radioautographic determinations of 125I-(Tyr0,D-Trp8)somatostatin-14 (125I-SRIF) binding sites were performed on frozen serial sections of the locus coeruleus (LC) of control rats and of rats subjected to either bilateral microinjections of 6 hydroxydopamine (6-OHDA) into the LC or unilateral microinjection into the ascending noradrenergic bundles. These experiments were performed in order to determine whether 125I-SRIF binding was localized to noradrenergic-containing cells and in which regions the cells which contain the binding sites are projecting. The extent of the lesions was assessed by measuring norepinephrine (NE) levels in the hippocampus (88% decrease as compared to sham-operated animals) for bilateral LC lesions and in the frontal cortex (87% reduction vs. contralateral side) for unilateral bundle lesions. In control rats, 125I-SRIF binding sites were restricted to the boundaries of the LC and followed closely the distribution of tyrosine hydroxylase-labeled cells. Three weeks after bilateral injections of 6-OHDA, 125I-SRIF binding decreased by 79% in all regions of the LC. In contrast, unilateral destruction of the ascending noradrenergic bundles resulted in a moderate decrease only in the middle part of the LC with a more important effect in the dorsal (55%) than in the ventral (24%) portion of the nucleus. These data demonstrate that: (1) most SRIF receptors in the LC are located in the vicinity of NE-containing cell bodies and (2) NE-containing cells bearing SRIF receptors project to the forebrain as well as to other terminal areas located more caudally in the brain. These data suggest a general role for SRIF in the control of the multiple functions of the LC.

• OSTI ID: 7016221
• Journal Information: Peptides (Fayetteville, New York); (USA), Journal Name: Peptides (Fayetteville, New York); (USA) Vol. 11:1; ISSN 0196-9781; ISSN PPTDD
• Country of Publication: United States
• Language: English

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550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ADRENAL HORMONES
AMINO ACIDS
ANIMAL CELLS
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
AUTORADIOGRAPHY
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL LOCALIZATION
BIOSYNTHESIS
BODY
BRAIN
CARBOXYLIC ACIDS
CARDIOTONICS
CARDIOVASCULAR AGENTS
CENTRAL NERVOUS SYSTEM
DAYS LIVING RADIOISOTOPES
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
ENZYMES
HYDROXY ACIDS
HYDROXYLASES
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPES
KINETICS
MAMMALS
MEMBRANE PROTEINS
NERVE CELLS
NERVOUS SYSTEM
NEUROREGULATORS
NORADRENALINE
NUCLEI
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
OXIDOREDUCTASES
PEPTIDES
PROTEINS
RADIOASSAY
RADIOISOTOPES
RATS
REACTION KINETICS
RECEPTORS
RODENTS
SOMATIC CELLS
SOMATOSTATIN
SYMPATHOMIMETICS
SYNTHESIS
TYROSINE
VERTEBRATES