Diurnal changes in pineal extracellular indoles of freely moving rats.
We observed 24 h changes of 'extracellular' indoleamines in pineal microdialysates taken from freely moving rats under a 12 h light/12 h dark cycle. Pineal indoleamines in microdialysates were analyzed by high-performance liquid chromatography with electrochemical detection. Consequently, they exhibited marked diurnal variations. The diurnal level in the extracellular 5-HT, higher for the light and lower for the dark, was parallel to that in 5-hydroxyindoleacetic acid and diametrically opposite to that in N-acetylserotonin (NAS). The release of 5-HT into the extracellular space transiently increased for the first 2 h after the dark onset and then became lower during the dark.
Azekawa
T
T
Department of Physiology, School of Medicine, University of Tokushima, Japan.
Sano
A
A
Sei
H
H
Morita
Y
Y
D000818:Animals; D002940:Circadian Rhythm; D003624:Darkness; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism*; D008027:Light; D008297:Male; D010870:Pineal Gland / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000031:analogs & derivatives / Q000378:metabolism*
D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; C006389:N-acetylserotonin