Effects of melatonin on 2-deoxy-(1-/sup 14/C)glucose uptake within rat suprachiasmatic nucleus
Previously, we have demonstrated that metabolic activity, shown by autoradiographic determination of 2-deoxy-(1-/sup 14/C)glucose (2-DG) uptake, within the rat hypothalamic suprachiasmatic nuclei (SCN) was inhibited by subcutaneous injection of 1 mg/kg melatonin. To determine whether this effect was specific to a particular time of day, the effects of melatonin on 2-DG uptake were studied in several hypothalamic areas, including the SCN, supraoptic nuclei (SON), lateral hypothalamic area (LHA), and anterior hypothalamic area (AHA) every 4 h throughout the circadian day. In a second experiment, the effects of different melatonin doses were studied at the time of day at which melatonin had its maximal effect to determine the dose-response relationship of melatonin-induced inhibition of SCN 2-DG uptake. The data indicate that melatonin inhibited 2-DG uptake in the SCN alone at one time of day, primarily at circadian time (CT) 6 and CT10, 2-6 h before subjective dusk, and secondarily at CT22, just before subjective dawn. This effect was dose dependent with a 50% effective dose of 1.49 +/- 2.30 micrograms/kg. The temporal and dose-response characteristics of these effects are similar to those characterizing the entraining effects of melatonin on circadian patterns of locomotion and drinking.
- Research Organization:
- State Univ. of New York, Stony Brook (USA)
- OSTI ID:
- 6805158
- Journal Information:
- Am. J. Physiol.; (United States), Vol. 255
- Country of Publication:
- United States
- Language:
- English
Similar Records
Suprachiasmatic nuclei of the fetal rat: characterization of a functional circadian clock using /sup 14/C-labeled deoxyglucose
Bilateral lesions of suprachiasmatic nuclei affect circadian rhythms in (/sup 3/H)-thymidine incorporation into deoxyribonucleic acid in mouse intestinal tract, mitotic index of corneal epithelium, and serum corticosterone
Related Subjects
GLUCOSE
MEMBRANE TRANSPORT
MELATONIN
BIOCHEMICAL REACTION KINETICS
AUTORADIOGRAPHY
CARBON 14 COMPOUNDS
DOSE-RESPONSE RELATIONSHIPS
HYPOTHALAMUS
RATS
ALDEHYDES
AMINES
ANIMALS
AROMATICS
AZAARENES
AZOLES
BODY
BRAIN
CARBOHYDRATES
CENTRAL NERVOUS SYSTEM
HETEROCYCLIC COMPOUNDS
HEXOSES
INDOLES
KINETICS
LABELLED COMPOUNDS
MAMMALS
MONOSACCHARIDES
NERVOUS SYSTEM
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PYRROLES
REACTION KINETICS
RODENTS
SACCHARIDES
TRYPTAMINES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques