Determination of pineal melatonin by high-performance liquid chromatography with electrochemical detection: application for rhythm studies and tissue explants.
High-pressure liquid chromatography with electrochemical detection has been used for the determination of melatonin in rat pineal glands and tissue explants. Rat pineal melatonin content was measured at 2-hr intervals during a 24-hr period by direct injection of supernatants from centrifuged pineal homogenates into a reversed-phase C18 column. The lower limit of sensitivity was 32 pg per gland for a 2:1 signal-to-noise ratio, which allows melatonin measurements during daytime. Both absolute values and circadian rhythmicity obtained with the present method are in agreement with previously validated radioimmunoassays. In addition, isoproterenol-induced release of melatonin from individual rat pineal explants was measured after chloroform extraction of the incubation medium.
Hernandez
G
G
Departamento de Fisiologia, Universidad de La Laguna, Tenerife, Spain.
Abreu
P
P
Alonso
R
R
Calzadilla
C H
CH
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D002940:Circadian Rhythm; D004563:Electrochemistry; D066298:In Vitro Techniques; D008297:Male; D008550:Melatonin / Q000032:analysis*; D010870:Pineal Gland / Q000032:analysis*; D051381:Rats; D011919:Rats, Inbred Strains
D008550:Melatonin