Plasma, cerebrospinal fluid, and brain distribution of /sup 14/C-melatonin in rat: a biochemical and autoradiographic study

Journal Article · Fri Jan 01 00:00:00 EST 1988 · J. Pineal Res.; (United States)

DOI:https://doi.org/10.1111/j.1600-079X.1988.tb00787.x· OSTI ID:6801024

Vitte, P A; Harthe, C; Lestage, P; Claustrat, B; Bobillier, P

The distribution of 14C-Melatonin (14C-MT) after systemic injection was studied in the plasma, cerebrospinal fluid (CSF), and brain of rats. Chromatographic analysis (thin-layer chromatography and high-performance liquid chromatography) indicated that the radioactivity from biological samples taken at various times following the injection of label was mainly associated with 14C-MT. Computer analysis of plasma 14C-MT kinetics showed a three-compartment system with half-lives of 0.21 +/- 0.05, 5.97 +/- 1.11, and 47.52 +/- 8.86 min. The volume of distribution and the clearance were 1,736 +/- 349 ml.kg-1 and 25.1 +/- 1.7 ml.min-1.kg-1 respectively. The entry of 14C-MT into the CSF was rapid and reached a maximum at 5 min. The decay followed a two-compartment system with half-lives of 16.5 +/- 2.9 and 47.3 +/- 8.6 min. The CSF/plasma concentration ratio was 0.38 at the steady state (30 min). At 2 min the level of 14C-MT in the brain was 3.8 higher than in the CSF. Representative autoradiograms revealed an heterogeneous localization of 14C-MT in the grey matter. The highest regional values, as evaluated by the permeability area product technique, were found in cortex, thalamic nuclei, medial geniculate nucleus, anterior pretectal area, paraventricular nucleus of the hypothalamus, choroid plexuses, and bulb-pons. Thirty minutes later 14C-MT was still detected in most of the brain regions analyzed. These results point to a low but rapid penetration of circulating MT into the brain and the CSF. The heterogeneous distribution and the partial retention of 14C-MT in the brain are compatible with the hypothesis of a central action of this hormone mediated via binding sites.

• Research Organization: Hopital Ste Eugenie St. Genis-Laval (France)
• OSTI ID: 6801024
• Journal Information: J. Pineal Res.; (United States), Vol. 5:5
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
MELATONIN
TISSUE DISTRIBUTION
AUTORADIOGRAPHY
BIOLOGICAL HALF-LIFE
BLOOD PLASMA
BLOOD-BRAIN BARRIER
BRAIN
CARBON 14 COMPOUNDS
CEREBROSPINAL FLUID
CHROMATOGRAPHY
LIQUID COLUMN CHROMATOGRAPHY
RATS
THIN-LAYER CHROMATOGRAPHY
AMINES
ANIMALS
AROMATICS
AZAARENES
AZOLES
BIOLOGICAL MATERIALS
BLOOD
BODY
BODY FLUIDS
CENTRAL NERVOUS SYSTEM
DISTRIBUTION
HETEROCYCLIC COMPOUNDS
INDOLES
LABELLED COMPOUNDS
MAMMALS
MATERIALS
NERVOUS SYSTEM
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PYRROLES
RODENTS
SEPARATION PROCESSES
TRYPTAMINES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques