caa a22 4500 477117325 CHVBK 20180405111626.0 cr unu---uuuuu 170330e19961101xx s 000 0 eng 10.1007/BF01875584 doi (NATIONALLICENCE)springer-10.1007/BF01875584 Production of melatonin by the gilthead sea bream pineal: an in vivo and in vitro study [Elektronische Daten] [Miguel Molina-Borja, Jack Falcón, J. Ravault] This study deals with the variations of plasma melatonin content and ofin vitro pineal melatonin secretion, in one year-old male sea bream. Plasma melatonin levels varied from almost undetectable levels during the day to 150-200 pg ml−1 during the night, in animals maintained under a light/dark (12L/12D) cycle. The duration of the nocturnal surge corresponded to the duration of the night. A similar pattern of melatonin secretion was obtainedin vitro, with pineals cultured under a 24h L/D cycle. When the photoperiod cycle was advanced by 8h, the first nocturnal peak in melatonin secretion was more acute compared to the profile described above, but the rhythmic variations were immediately synchronized to the new L/D conditions. Under constant darkness (D/D), circadian variations in melatonin release were observed for no more than two 24h cycles. No melatonin was detected in the culture media from retinas cultured under L/D or under D/D. These results strongly suggest that the pineal is the major source of plasma melatonin in the gilthead sea bream, and that the 24h photoperiod cycle is a powerful synchronizer of the rhythmic production of melatonin by this organ. Kugler Publication, 1996 pineal nationallicence retina nationallicence melatonin nationallicence nycthemeral rhythms nationallicence circadian oscillators nationallicence blood nationallicence culture nationallicence Molina-Borja Miguel Departamento de Biología Animal, Facultad de Biología, Universidad de La Laguna, Tenerife, Canary Islands, Spain aut Falcón Jack Laboratoire de Neurobiologie et Neuroendocrinologie Cellulaires, URA CNRS 1869, Université de Poitiers, 40 avenue du Recteur Pineau, 86022, Poitiers Cedex, France aut Ravault J. INRA, Station de Physiologie de la Reproduction et Laboratoire de Neuroendocrinologie, Université de Tours, 37200, Tours, France aut Fish Physiology and Biochemistry Kluwer Academic Publishers 15/5(1996-11-01), 413-419 0920-1742 15:5<413 1996 15 10695 https://doi.org/10.1007/BF01875584 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF01875584 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Molina-Borja Miguel Departamento de Biología Animal, Facultad de Biología, Universidad de La Laguna, Tenerife, Canary Islands, Spain aut NATIONALLICENCE 700 1- Falcón Jack Laboratoire de Neurobiologie et Neuroendocrinologie Cellulaires, URA CNRS 1869, Université de Poitiers, 40 avenue du Recteur Pineau, 86022, Poitiers Cedex, France aut NATIONALLICENCE 700 1- Ravault J. INRA, Station de Physiologie de la Reproduction et Laboratoire de Neuroendocrinologie, Université de Tours, 37200, Tours, France aut NATIONALLICENCE 773 0- Fish Physiology and Biochemistry Kluwer Academic Publishers 15/5(1996-11-01), 413-419 0920-1742 15:5<413 1996 15 10695 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer