Plasma 6-hydroxymelatonin, 6-sulfatoxymelatonin and melatonin kinetics after melatonin administration to rats.
A specific, sensitive and reproducible high-performance liquid chromatographic (HPLC) method is described for the simultaneous measurement of 6-hydroxymelatonin and melatonin in rat plasma. Using this technique, a dose-dependent increase in 6-hydroxymelatonin concentration was observed 10 min after administration of different doses of melatonin. Plasma 6-hydroxymelatonin represented 1% of plasma melatonin, irrespective of the melatonin dose administered. After administration of 100 micrograms melatonin, 6-hydroxymelatonin could be detected in plasma from 7.5 to 60 min. In the same experiment, plasma 6-sulfatoxymelatonin concentrations determined by radioimmunoassay could be detected from 7.5 to 120 min. This HPLC technique allows the measurement of 6-hydroxymelatonin together with melatonin. Combined with an RIA for 6-sulfatoxymelatonin, it could be useful in determining the site of action of drugs affecting melatonin metabolism.
Raynaud
F
F
URA-CNRS 1332, Neurobiologie des fonctions rythmiques et saisonnières, Université Louis-Pasteur, Strasbourg, France.
Mauviard
F
F
Geoffriau
M
M
Claustrat
B
B
Pevet
P
P
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D008297:Male; D008550:Melatonin / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics / Q000494:pharmacology*; D011863:Radioimmunoassay; D051381:Rats; D017208:Rats, Wistar
C054513:6-sulfatoxymelatonin; D008550:Melatonin; C012365:6-hydroxymelatonin