{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,18]],"date-time":"2026-09-18T04:59:16Z","timestamp":1789707556910,"version":"4.0.1"},"reference-count":80,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2014,7,16]],"date-time":"2014-07-16T00:00:00Z","timestamp":1405468800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"funder":[{"name":"the National Science Centre of Poland","award":["No. NN 308 069937"],"award-info":[{"award-number":["No. NN 308 069937"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>This study characterizes the diurnal profiles of ten melatonin synthesis-related indoles, the quantitative relations between these compounds, and daily variations in the contents of catecholamines and their metabolites in the domestic duck pineal organ. Fourteen-week-old birds, which were reared under a 12L:12D cycle, were killed at  two-hour intervals. The indole contents were measured using HPLC with fluorescence detection, whereas the levels of catecholamines and their metabolites were measured using HPLC with electrochemical detection. All indole contents, except for tryptophan, showed significant diurnal variations. The 5-hydroxytryptophan level was approximately two-fold higher during the scotophase than during the photophase. The serotonin content increased during the first half of the photophase, remained elevated for approximately 10 h and then rapidly decreased in the middle of the scotophase. N-acetylserotonin showed the most prominent changes, with a more than 15-fold increase at night. The melatonin cycle demonstrated only an approximately 5-fold difference between the peak and nadir. The  5-methoxytryptamine content was markedly elevated during the scotophase. The  5-hydroxyindole acetic acid, 5-hydroxytryptophol, 5-methoxyindole acetic acid and  5-methoxytryptophol profiles were analogous to the serotonin rhythm. The norepinephrine and dopamine contents showed no significant changes. The DOPA, DOPAC and homovanillic acid levels were higher during the scotophase than during the photophase. Vanillylmandelic acid showed the opposite rhythm, with an elevated level during  the daytime.<\/jats:p>","DOI":"10.3390\/ijms150712604","type":"journal-article","created":{"date-parts":[[2014,7,16]],"date-time":"2014-07-16T11:47:18Z","timestamp":1405511238000},"page":"12604-12630","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":17,"title":["Diurnal Profiles of Melatonin Synthesis-Related  Indoles, Catecholamines and Their Metabolites in the  Duck Pineal Organ"],"prefix":"10.3390","volume":"15","author":[{"given":"Bogdan","family":"Lewczuk","sequence":"first","affiliation":[{"name":"Department of Histology and Embryology, Faculty of Veterinary Medicine,  University of Warmia and Mazury in Olsztyn, Oczapowskiego Str. 13, 10-719 Olsztyn, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Natalia","family":"Zi\u00f3\u0142kowska","sequence":"additional","affiliation":[{"name":"Department of Histology and Embryology, Faculty of Veterinary Medicine,  University of Warmia and Mazury in Olsztyn, Oczapowskiego Str. 13, 10-719 Olsztyn, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Magdalena","family":"Prusik","sequence":"additional","affiliation":[{"name":"Department of Histology and Embryology, Faculty of Veterinary Medicine,  University of Warmia and Mazury in Olsztyn, Oczapowskiego Str. 13, 10-719 Olsztyn, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Barbara","family":"Przybylska-Gornowicz","sequence":"additional","affiliation":[{"name":"Department of Histology and Embryology, Faculty of Veterinary Medicine,  University of Warmia and Mazury in Olsztyn, Oczapowskiego Str. 13, 10-719 Olsztyn, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2014,7,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"151","DOI":"10.1210\/edrv-12-2-151","article-title":"Pineal melatonin: Cell biology of its synthesis and of its physiological interactions","volume":"12","author":"Reiter","year":"1991","journal-title":"Endocr. Rev."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"325","DOI":"10.1124\/pr.55.2.2","article-title":"Generation of the melatonin endocrine message in mammals: A review of the complex regulations of melatonin synthesis by norepinephrine, peptides and other pineal transmitters","volume":"55","author":"Simonneaux","year":"2003","journal-title":"Pharmacol. Rev."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"168","DOI":"10.2174\/157015910792246164","article-title":"Melatonin metabolism in the central nervous system","volume":"8","author":"Hardeland","year":"2010","journal-title":"Curr. Neuropharmacol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"654","DOI":"10.1007\/BF01923947","article-title":"The melatonin rhythm: Both a clock and a calendar","volume":"49","author":"Reiter","year":"1993","journal-title":"Experientia"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2001","DOI":"10.1007\/s00018-008-8001-x","article-title":"Melatonin, hormone of darkness and more: Occurrence, control mechanisms, actions and bioactive metabolites","volume":"65","author":"Hardeland","year":"2008","journal-title":"Cell Mol. Life Sci."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"101","DOI":"10.1111\/j.1749-6632.2009.04435.x","article-title":"Structural and functional evolution of the pineal melatonin system in vertebrates","volume":"1163","author":"Besseau","year":"2009","journal-title":"Ann. N. Y. Acad. Sci."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"4233","DOI":"10.1074\/jbc.R600036200","article-title":"Arylalkylamine N-acetyltransferase: \u201cThe Timezyme\u201d","volume":"282","author":"Klein","year":"2007","journal-title":"J. Biol. Chem."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"142","DOI":"10.1016\/j.tem.2007.03.001","article-title":"The mammalian pineal gland: Known facts, unknown facets","volume":"18","author":"Maronde","year":"2007","journal-title":"Trends Endocrinol. Metab."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"312","DOI":"10.1177\/074873001129002033","article-title":"Of rodents and ungulates and melatonin: Creating a uniform code for darkness by different signaling mechanisms","volume":"16","author":"Stehle","year":"2001","journal-title":"J. Biol. Rhythms."},{"key":"ref_10","first-page":"581","article-title":"N-bromoacetyltryptamine strongly and reversibly inhibits in vitro melatonin secretion from mammalian pinealocytes","volume":"26","author":"Lewczuk","year":"2005","journal-title":"Neuro Endocrinol. Lett."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"72","DOI":"10.1002\/jemt.1070","article-title":"Photoreception and circadian clock system of the chicken pineal gland","volume":"53","author":"Okano","year":"2001","journal-title":"Microsc. Res. Tech."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"160","DOI":"10.1016\/j.bbrc.2004.11.022","article-title":"Circadian gene expression patterns of melanopsin and pinopsin in the chick pineal gland","volume":"326","author":"Holthues","year":"2005","journal-title":"Biochem. Biophys. Res. Commun."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1385\/MN:25:1:019","article-title":"Circadian clock system in the pineal gland","volume":"25","author":"Fukada","year":"2002","journal-title":"Mol. Neurobiol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"80","DOI":"10.1046\/j.1600-079X.2003.00101.x","article-title":"Suppression of melatonin biosynthesis in the chicken pineal gland by retinally perceived light-involvement of D1-dopamine receptors","volume":"36","author":"Zawilska","year":"2004","journal-title":"J. Pineal Res."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"97","DOI":"10.1002\/cne.20935","article-title":"Chicken suprachiasmatic nuclei: I. Efferent and afferent connections","volume":"496","author":"Cantwell","year":"2006","journal-title":"J. Comp. Neurol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"187","DOI":"10.1007\/BF00188110","article-title":"Hypothalamic regulation of circadian noradrenergic input to the chick pineal gland","volume":"167","author":"Cassone","year":"1990","journal-title":"J. Comp. Physiol. A"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"3665","DOI":"10.1523\/JNEUROSCI.07-11-03665.1987","article-title":"Alpha-2 adrenergic regulation of melatonin release in chick pineal cell cultures","volume":"7","author":"Pratt","year":"1987","journal-title":"J. Neurosci."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"209","DOI":"10.1016\/0006-8993(94)90699-8","article-title":"Comparison of circadian oscillation of melatonin release in pineal cells of house sparrow, pigeon and Japanese quail, using cell perfusion system","volume":"651","author":"Murakami","year":"1994","journal-title":"Brain Res."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1007\/s00441-002-0571-6","article-title":"Rhythm and soul in the avian pineal","volume":"309","author":"Natesan","year":"2002","journal-title":"Cell Tissue Res."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"249","DOI":"10.1016\/0006-8993(92)90636-N","article-title":"The superior cervical ganglia are not necessary for entrainment or persistence of the pineal melatonin rhythm in Japanese quail","volume":"569","author":"Barrett","year":"1992","journal-title":"Brain Res."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1016\/S0378-4347(00)00064-5","article-title":"Separation and assay methods for melatonin and its precursors","volume":"747","author":"Harumi","year":"2000","journal-title":"J. Chromatogr. B: Biomed. Sci. Appl."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"103","DOI":"10.1016\/0378-4347(91)80073-L","article-title":"Determination of 5-methoxyindoles in pineal gland and plasma samples by high-performance liquid chromatography with electrochemical detection","volume":"564","author":"Raynaud","year":"1991","journal-title":"J. Chromatogr."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"77","DOI":"10.1016\/S0304-3940(97)13403-6","article-title":"Daily time course of the contents in monoamines and their metabolites in the pineal gland of Syrian hamster","volume":"223","author":"Moujir","year":"1997","journal-title":"Neurosci. Lett."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"106","DOI":"10.1111\/j.1600-079X.1998.tb00547.x","article-title":"Changes with age in daytime and nighttime contents of melatonin, indoleamines, and catecholamines in the pineal gland: A comparative study in rat and Syrian hamster","volume":"25","author":"Miguez","year":"1998","journal-title":"J. Pineal Res."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"67","DOI":"10.1016\/j.ygcen.2005.04.010","article-title":"Indoleamines and 5-methoxyindoles in trout pineal organ in vivo: Daily changes and influence of photoperiod","volume":"144","author":"Ceinos","year":"2005","journal-title":"Gen. Comp. Endocrinol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"928","DOI":"10.1242\/jeb.051516","article-title":"Changes in plasma melatonin levels and pineal organ melatonin synthesis following acclimation of rainbow trout (Oncorhynchus mykiss) to different water salinities","volume":"214","author":"Gesto","year":"2011","journal-title":"J. Exp. Biol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1016\/S0378-4347(00)82367-1","article-title":"Determination of six indolic compounds, including melatonin, in rat pineal using high-performance liquid chromatography with serial fluorometric-electrochemical detection","volume":"528","author":"Chin","year":"1990","journal-title":"J. Chromatogr. B: Biomed. Sci. Appl."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"155","DOI":"10.1016\/S0378-4347(00)80428-4","article-title":"Determination of indoles in human and rat pineal","volume":"228","author":"Anderson","year":"1982","journal-title":"J. Chromatogr."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"2173","DOI":"10.1016\/j.jchromb.2009.06.001","article-title":"A simple and sensitive method for determination of melatonin in plasma, bile and intestinal tissues by high performance liquid chromatography with fluorescence detection","volume":"877","author":"Ceinos","year":"2009","journal-title":"J. Chromatogr. B Anal. Technol. Biomed. Life Sci."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"237","DOI":"10.1016\/S1570-0232(04)00670-1","article-title":"A sensitive internal standard method for the determination of melatonin in mammals using precolumn oxidation reversed-phase high-performance liquid chromatography","volume":"811","author":"Hamase","year":"2004","journal-title":"J. Chromatogr. B Anal. Technol. Biomed. Life Sci."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"281","DOI":"10.2116\/analsci.22.281","article-title":"Simultaneous liquid chromatographic measurement of melatonin and related indoles through post-column electrochemical demethylation and fluorescence derivatization","volume":"22","author":"Todoroki","year":"2006","journal-title":"Anal. Sci."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1034\/j.1600-079X.2000.290101.x","article-title":"Phase-shifting effects of light on the circadian rhythms of 5-methoxytryptophol and melatonin in the chick pineal gland","volume":"29","author":"Zawilska","year":"2000","journal-title":"J. Pineal Res."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"214","DOI":"10.1034\/j.1600-079X.2002.01835.x","article-title":"Daily variation in the concentration of 5-methoxytryptophol and melatonin in the duck pineal gland and plasma","volume":"32","author":"Zawilska","year":"2002","journal-title":"J. Pineal Res."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"296","DOI":"10.1016\/S0016-6480(03)00269-7","article-title":"Daily variation in the concentration of melatonin and 5-methoxytryptophol in the goose pineal gland, retina, and plasma","volume":"134","author":"Zawilska","year":"2003","journal-title":"Gen. Comp. Endocrinol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"141","DOI":"10.1016\/0742-8413(84)90061-6","article-title":"Day\/night differences in pineal indoles in the adult pigeon (Columba livia)","volume":"78","author":"Grady","year":"1984","journal-title":"Comp. Biochem. Physiol. C"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"334","DOI":"10.1016\/0006-8993(86)91169-8","article-title":"Dynamics of noradrenergic circadian input to the chicken pineal gland","volume":"384","author":"Cassone","year":"1986","journal-title":"Brain Res."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"722","DOI":"10.1111\/j.1471-4159.1992.tb09777.x","article-title":"Monoamines and their precursors and metabolites in the chicken brain, pineal, and retina: Regional distribution and day\/night variation","volume":"58","author":"Siuciak","year":"1992","journal-title":"J. Neurochem."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"145","DOI":"10.1016\/S1570-0232(01)00639-0","article-title":"Novel and sensitive high-performance liquid chromatographic method based on electrochemical coulometric array detection for simultaneous determination of catecholamines, kynurenine and indole derivatives of tryptophan","volume":"769","author":"Vaarmann","year":"2002","journal-title":"J. Chromatogr.B Anal. Technol. Biomed. Life Sci."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"134","DOI":"10.2174\/1874453201003010134","article-title":"Season-related differences in the biosynthetic activity of the neonatal chicken pineal gland","volume":"3","author":"Piesiewicz","year":"2010","journal-title":"Open Ornithol. J."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1556\/ABiol.52.2001.1.1","article-title":"A reproductive phase-dependent effect of dietary l-tryptophan on pineal gland and gonad of a nocturnal bird, Indian spotted owlet Athene brama","volume":"52","author":"Guchhait","year":"2001","journal-title":"Acta Biol. Hung."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"769","DOI":"10.1111\/j.1471-4159.1985.tb12881.x","article-title":"Ovine pineal indoles: Effects of l-tryptophan or l-5-hydroxytryptophan administration","volume":"44","author":"Sugden","year":"1985","journal-title":"J. Neurochem."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"291","DOI":"10.1159\/000125600","article-title":"Tryptophan administration inhibits nocturnal N-acetyltransferase activity and melatonin content in the rat pineal gland. Evidence that serotonin modulates melatonin production via a receptor-mediated mechanism","volume":"52","author":"Reiter","year":"1990","journal-title":"Neuroendocrinology"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"52","DOI":"10.1111\/j.1742-7843.2008.00333.x","article-title":"Circadian levels of serotonin in plasma and brain after oral administration of tryptophan in rats","volume":"104","author":"Mateos","year":"2009","journal-title":"Basic Clin. Pharmacol.Toxicol."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"139","DOI":"10.1111\/j.1600-079X.1995.tb00183.x","article-title":"Daily variation in the content of indoleamines, catecholamines and related compounds in the pineal gland of Syrian hamsters kept under long and short photoperiods","volume":"19","author":"Miguez","year":"1995","journal-title":"J. Pineal Res."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1111\/j.1600-079X.1996.tb00265.x","article-title":"Diurnal changes in the content of indoleamines, catecholamines, and methoxyindoles in the pineal gland of the Djungarian hamster (Phodopus sungorus): Effect of photoperiod","volume":"21","author":"Recio","year":"1996","journal-title":"J. Pineal Res."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"245","DOI":"10.1016\/0197-0186(95)00037-9","article-title":"Melatonin synthesis in the retina and pineal gland of Djungarian hamsters at different times of the year","volume":"27","author":"Steinlechner","year":"1995","journal-title":"Neurochem. Int."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/0006-8993(96)00743-3","article-title":"Tryptophan hydroxylase mRNA levels are regulated by the circadian clock, temperature, and cAMP in chick pineal cells","volume":"738","author":"Green","year":"1996","journal-title":"Brain Res."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"241","DOI":"10.1177\/074873049601100306","article-title":"Quantitative two-dimensional gel electrophoretic analysis of clock-controlled proteins in cultured chick pineal cells: Circadian regulation of tryptophan hydroxylase","volume":"11","author":"Florez","year":"1996","journal-title":"J. Biol. Rhythm."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"242","DOI":"10.1046\/j.1471-4159.1996.67010242.x","article-title":"Regulation of tryptophan hydroxylase by cyclic AMP, calcium, norepinephrine, and light in cultured chick pineal cells","volume":"67","author":"Florez","year":"1996","journal-title":"J. Neurochem."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"52","DOI":"10.1016\/0016-6480(71)90207-3","article-title":"A diurnal serotonin cycle in the pineal body of Japanese quail: Photoperiod phasing and the effect of superior cervical ganglionectomy","volume":"16","author":"Hedlund","year":"1971","journal-title":"Gen. Comp. Endocrinol."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"66","DOI":"10.1111\/j.1600-079X.2005.00214.x","article-title":"Seasonality of pineal gland activity and immune functions in chickens","volume":"39","author":"Majewski","year":"2005","journal-title":"J. Pineal Res."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"1227","DOI":"10.3109\/07420528.2012.719964","article-title":"Season-dependent postembryonic maturation of the diurnal rhythm of melatonin biosynthesis in the chicken pineal gland","volume":"29","author":"Piesiewicz","year":"2012","journal-title":"Chronobiol. Int."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"1582","DOI":"10.1210\/endo-113-5-1582","article-title":"Reciprocal day\/night relationship between serotonin oxidation and N-acetylation products in the rat pineal gland","volume":"113","author":"Mefford","year":"1983","journal-title":"Endocrinology"},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"237","DOI":"10.1007\/s11154-009-9125-5","article-title":"Melatonin formation in mammals: In vivo perspectives","volume":"10","author":"Chattoraj","year":"2009","journal-title":"Rev. Endocr. Metab. Disord."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"12","DOI":"10.1186\/1740-3391-4-12","article-title":"Relationship between nocturnal serotonin surge and melatonin onset in rodent pineal gland","volume":"4","author":"Liu","year":"2006","journal-title":"J. Circadian Rhythm."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1006\/gcen.1997.7014","article-title":"Indoleamine metabolism in the pineal gland of the Chinese hamster, Cricetulus griseus","volume":"109","author":"Harumi","year":"1998","journal-title":"Gen. Comp. Endocrinol."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"670","DOI":"10.1520\/JFS2004346","article-title":"Utilizing the urinary 5-HTOL\/5-HIAA ratio to determine ethanol origin in civil aviation accident victims","volume":"50","author":"Johnson","year":"2005","journal-title":"J. Forensic Sci."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"410","DOI":"10.1016\/j.ygcen.2008.01.003","article-title":"Food deprivation and refeeding effects on pineal indoles metabolism and melatonin synthesis in the rainbow trout Oncorhynchus mykiss","volume":"156","author":"Ceinos","year":"2008","journal-title":"Gen. Comp. Endocrinol."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/0024-3205(86)90430-3","article-title":"Correlations of serotonin and its metabolites in individual rat pineal glands over light: Dark cycles and after acute light exposure","volume":"39","author":"McNulty","year":"1986","journal-title":"Life Sci."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"464","DOI":"10.1159\/000123423","article-title":"Factors influencing melatonin, 5-hydroxytryptophol, 5-hydroxyindoleacetic acid, 5-hydroxytryptamine and tryptophan in rat pineal glands","volume":"35","author":"Young","year":"1982","journal-title":"Neuroendocrinology"},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"91","DOI":"10.1111\/j.1600-079X.2005.00223.x","article-title":"N-acetyltransferase is not the rate limiting enzyme of melatonin synthesis at night","volume":"39","author":"Liu","year":"2005","journal-title":"J. Pineal Res."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"254","DOI":"10.1016\/0006-8993(94)01339-J","article-title":"Effect of photoperiod on the diurnal melatonin and 5-methoxytryptophol rhythms in the human pineal gland","volume":"671","author":"Hofman","year":"1995","journal-title":"Brain Res."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"28","DOI":"10.1111\/j.1600-079X.1992.tb00051.x","article-title":"Seasonal variations in pineal 5-methoxytryptophol (5-ML) concentrations and in the daily pattern of pineal 5-ML and melatonin in the desert rodent Jaculus orientalis: Effect of prolonged illumination during the night","volume":"13","author":"Pevet","year":"1992","journal-title":"J. Pineal Res."},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"1132","DOI":"10.1006\/bbrc.1995.1615","article-title":"Mass spectrometric identification and quantification of endogenous 5-methoxyindole-3-acetic acid in quail tissues","volume":"209","author":"Tsang","year":"1995","journal-title":"Biochem. Biophys. Res. Commun."},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"293","DOI":"10.1007\/BF01252040","article-title":"Changes in the circadian rhythmicity of hydroxyindole-O-methyl transferase (HIOMT) activity in the synthesis of 5-methoxyindoles in the pineal gland of 28 day old male Wistar rats exposed to white, red and green light","volume":"53","author":"Balemans","year":"1982","journal-title":"J. Neural Transm."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/S0378-4347(00)84685-X","article-title":"Analysis of melatonin, 5-methoxytryptophol and 5-methoxyindoleacetic acid in the pineal gland and retina of hamster by capillary column gas chromatography-mass spectrometry","volume":"311","author":"Beck","year":"1984","journal-title":"J. Chromatogr."},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1016\/0006-8993(91)90286-5","article-title":"Melatonin deacetylation: Retinal vertebrate class distribution and Xenopus laevis tissue distribution","volume":"559","author":"Grace","year":"1991","journal-title":"Brain Res."},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"2013","DOI":"10.1111\/j.1471-4159.1981.tb10827.x","article-title":"In vivo formation of 5-methoxytryptamine from melatonin in rat","volume":"36","author":"Beck","year":"1981","journal-title":"J. Neurochem."},{"key":"ref_69","doi-asserted-by":"crossref","first-page":"389","DOI":"10.1677\/joe.0.1180389","article-title":"Day-night rhythm of 5-methoxytryptamine biosynthesis in the pineal gland of the golden hamster (Mesocricetus auratus)","volume":"118","author":"Galzin","year":"1988","journal-title":"J. Endocrinol."},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1016\/S0304-3940(97)00361-3","article-title":"Identification and diurnal studies of pineal and serum 5-methoxytryptamine in the rat and quail","volume":"228","author":"Li","year":"1997","journal-title":"Neurosci. Lett."},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"165","DOI":"10.1006\/gcen.1996.0018","article-title":"Secretion of the methoxyindoles melatonin, 5-methoxytryptophol, 5-methoxyindoleacetic acid, and 5-methoxytryptamine from trout pineal organs in superfusion culture: Effects of light intensity","volume":"101","author":"Meissl","year":"1996","journal-title":"Gen. Comp. Endocrinol."},{"key":"ref_72","doi-asserted-by":"crossref","first-page":"123","DOI":"10.1111\/j.1600-079X.2004.00182.x","article-title":"Posthatching developmental changes in noradrenaline content in the chicken pineal gland","volume":"38","author":"Zawilska","year":"2005","journal-title":"J. Pineal Res."},{"key":"ref_73","doi-asserted-by":"crossref","first-page":"2","DOI":"10.1002\/jemt.1063","article-title":"Sensory and endocrine characteristics of the avian pineal organ","volume":"53","author":"Sato","year":"2001","journal-title":"Microsc. Res. Tech."},{"key":"ref_74","doi-asserted-by":"crossref","first-page":"748","DOI":"10.1046\/j.1471-4159.1996.66020748.x","article-title":"Norepinephrine release in the rat pineal gland: The input from the biological clock measured by in vivo microdialysis","volume":"66","author":"Drijfhout","year":"1996","journal-title":"J. Neurochem."},{"key":"ref_75","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1111\/j.1600-079X.1994.tb00109.x","article-title":"Immunohistochemical studies on the coexistence of catecholamine-synthesizing enzymes and neuropeptide Y in nerve fibers of the porcine pineal gland","volume":"17","author":"Kaleczyc","year":"1994","journal-title":"J. Pineal Res."},{"key":"ref_76","doi-asserted-by":"crossref","first-page":"139","DOI":"10.1007\/s00441-002-0580-5","article-title":"The anatomy and innervation of the mammalian pineal gland","volume":"309","author":"Baeres","year":"2002","journal-title":"Cell Tissue Res."},{"key":"ref_77","first-page":"193","article-title":"Specific distribution pattern of nerve fibers containing catecholamine-synthesizing enzymes, neuropeptide Y (NPY) and C-terminal flanking peptide of NPY (CPON) in the pineal gland of the chinchilla (Chinchilla laniger)\u2014An immunohistochemical study","volume":"41","author":"Nowicki","year":"2003","journal-title":"Folia Histochem. Cytobiol."},{"key":"ref_78","doi-asserted-by":"crossref","unstructured":"Acu\u00f1a-Castroviejo, D., Escames, G., Venegas, C., D\u00edaz-Casado, M.E., Lima-Cabello, E., L\u00f3pez, L.C., Rosales-Corral, S., Tan, D.X., and Reiter, R.J. (2014). Extrapineal melatonin: Sources, regulation, and potential functions. Cell. Mol. Life Sci., 2014.","DOI":"10.1007\/s00018-014-1579-2"},{"key":"ref_79","doi-asserted-by":"crossref","first-page":"3335","DOI":"10.1046\/j.1432-1033.2003.03708.x","article-title":"Characterization of the serotoninergic system in the C57BL\/6 mouse skin","volume":"270","author":"Slominski","year":"2003","journal-title":"Eur. J. Biochem."},{"key":"ref_80","doi-asserted-by":"crossref","first-page":"176","DOI":"10.1096\/fj.04-2079rev","article-title":"The cutaneous serotoninergic\/melatoninergic system: Securing a place under the sun","volume":"19","author":"Slominski","year":"2005","journal-title":"FASEB J."}],"container-title":["International Journal of Molecular Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1422-0067\/15\/7\/12604\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T21:13:40Z","timestamp":1760217220000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1422-0067\/15\/7\/12604"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2014,7,16]]},"references-count":80,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2014,7]]}},"alternative-id":["ijms150712604"],"URL":"https:\/\/doi.org\/10.3390\/ijms150712604","relation":{},"ISSN":["1422-0067"],"issn-type":[{"value":"1422-0067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2014,7,16]]}}}