Development of regulation of melatonin release in pineal cells in chick embryo.
Melatonin release in a pineal cell culture from 13- and 14-day-old chick embryos increased during the dark phase and decreased during the light phase of a 12 h light:12 h dark cycle. When the light-dark cycle was reversed, the pattern of melatonin release in the culture also reversed. 8-Bromo cyclic-AMP stimulated melatonin release in both the light and dark phases. However, no rhythm of melatonin release was detected under constant dark (DD) conditions in a cell culture from 14-day-old chick embryos. In 18-day-old chick embryos, the pineal cell culture expressed a circadian rhythm of melatonin release under DD conditions. These results indicate that mechanisms regulating melatonin synthesis in the avian pineal gland are established during embryonic life.
Department of Veterinary Physiology, Faculty of Agriculture, Miyazaki University, Japan.
K
K
Akasaka
T
T
Nasu
T
T
Katayama
N
N
Murakami
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000818:Animals; D002478:Cells, Cultured; D002642:Chick Embryo; D003624:Darkness; D008027:Light; D008550:Melatonin / Q000378:metabolism*; D010870:Pineal Gland / Q000166:cytology / Q000196:embryology* / Q000378:metabolism*
D015124:8-Bromo Cyclic Adenosine Monophosphate; D008550:Melatonin