Putative melatonin receptors in a human biological clock

Journal Article · Fri Oct 07 00:00:00 EDT 1988 · Science (Washington, D.C.); (United States)

DOI:https://doi.org/10.1126/science.2845576· OSTI ID:6605892

Reppert, S M; Weaver, D R; Rivkees, S A; Stopa, E G

In vitro autoradiography with /sup 125/I-labeled melatonin was used to examine melatonin binding sites in human hypothalamus. Specific /sup 125/I-labeled melatonin binding was localized to the suprachiasmatic nuclei, the site of a putative biological clock, and was not apparent in other hypothalamic regions. Specific /sup 125/I-labeled melatonin binding was consistently found in the suprachiasmatic nuclei of hypothalami from adults and fetuses. Densitometric analysis of competition experiments with varying concentrations of melatonin showed monophasic competition curves, with comparable half-maximal inhibition values for the suprachiasmatic nuclei of adults (150 picomolar) and fetuses (110 picomolar). Micromolar concentrations of the melatonin agonist 6-chloromelatonin completely inhibited specific /sup 125/I-labeled melatonin binding, whereas the same concentrations of serotonin and norepinephrine caused only a partial reduction in specific binding. The results suggest that putative melatonin receptors are located in a human biological clock.

• Research Organization: Laboratory of Developmental Chronobiology, Boston, MA (USA)
• OSTI ID: 6605892
• Journal Information: Science (Washington, D.C.); (United States), Vol. 242:4875
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
MELATONIN
RECEPTORS
BIOLOGICAL LOCALIZATION
AUTORADIOGRAPHY
BIOCHEMICAL REACTION KINETICS
HYPOTHALAMUS
IODINE 125
MAN
AMINES
ANIMALS
AROMATICS
AZAARENES
AZOLES
BETA DECAY RADIOISOTOPES
BODY
BRAIN
CENTRAL NERVOUS SYSTEM
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
HETEROCYCLIC COMPOUNDS
INDOLES
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPES
KINETICS
MAMMALS
MEMBRANE PROTEINS
NERVOUS SYSTEM
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PRIMATES
PROTEINS
PYRROLES
RADIOISOTOPES
REACTION KINETICS
TRYPTAMINES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques