Seasonal variations in the daily rhythm of pineal gland and/or circulating melatonin and 5-methoxytryptophol concentrations in the European hamster, Cricetus cricetus.
Day-night variations in pineal and/or circulating melatonin and 5-methoxytryptophol (5-ML) concentrations were measured monthly throughout the year in female European hamsters, Cricetus cricetus, maintained under natural conditions. Pronounced seasonal variations in the day-night rhythm of both melatonin and 5-ML were observed. As previously reported for melatonin, the daily rhythm of both methoxyindoles disappeared in spring and early summer, while a clear day-night rhythm occurred in autumn, winter, and early spring. The amplitude of the day-night variations appeared to be maximum from October until January. An inverse relationship existed between the rhythms of melatonin and 5-ML.
Vivien-Roels
B
B
URA CNRS 1332, Université Louis Pasteur, Strasbourg, France.
Pevet
P
P
Masson-Pevet
M
M
Canguilhem
B
B
D000818:Animals; D002940:Circadian Rhythm / Q000502:physiology*; D006224:Cricetinae / Q000097:blood* / Q000502:physiology; D005260:Female; D007211:Indoles / Q000097:blood*; D008550:Melatonin / Q000097:blood*; D010870:Pineal Gland / Q000502:physiology*; D012621:Seasons
D007211:Indoles; C002465:methoxytryptophol; D008550:Melatonin