Iron decreases the nuclear but not the cytosolic content of the neurohormone melatonin in several tissues in chicks

This paper describes the influence of iron on both nuclear and cytosolic melatonin contents in several tissues of chicks. The neurohormone melatonin was estimated by means of radioimmunoassay. Iron, administered as FeCl3, decreased the nuclear melatonin level in a variety of tissues, including brain, heart, lung, kidney, and erythrocytes (nucleated cells in chicks) but was not seen in either the liver or gut. All variations related with iron were seen in the nuclear fraction, while only in the pineal gland did the melatonin content of the cytosol change as a result of iron treatment. We also observed a day‐night rhythm in the nuclear melatonin: high nuclear levels of melatonin at night and low levels during the light period. This is the first report of nuclear localization of melatonin in any avian cell. © 1996 Wiley‐Liss, Inc.

[1]  R. Reiter,et al.  Characterization of high‐affinity melatonin binding sites in purified cell nuclei of rat liver , 1994, Journal of pineal research.

[2]  R. Reiter,et al.  Nuclear localization of melatonin in different mammalian tissues: Immunocytochemical and radioimmunoassay evidence , 1993, Journal of cellular biochemistry.

[3]  R. Reiter,et al.  Melatonin receptors in purified cell nuclei of liver. , 1993, Research communications in chemical pathology and pharmacology.

[4]  M. Pablos,et al.  Effect of iron and estrogen on melatonin secretion by the chicken pineal gland , 1993, Neuroscience Letters.

[5]  R. Reiter,et al.  Distribution of melatonin in mammalian tissues: The relative importance of nuclear versus cytosolic localization , 1993, Journal of pineal research.

[6]  C. Rodríguez,et al.  5-Aminolevulinate synthase mRNA levels in the Harderian gland of Syrian hamsters: Correlation with porphyrin concentrations and regulation by androgens and melatonin , 1991, Molecular and Cellular Endocrinology.

[7]  R. Reiter,et al.  Pineal melatonin: cell biology of its synthesis and of its physiological interactions. , 1991, Endocrine reviews.

[8]  J. Zawilska,et al.  Arylalkylamine (serotonin) N-acetyltransferase assay using high-performance liquid chromatography with fluorescence or electrochemical detection of N-acetyltryptamine. , 1990, Analytical biochemistry.

[9]  B. Maiti,et al.  Pineal activity during the seasonal gonadal cycle in a wild avian species, the tree pie (Dendrocitta vagabunda). , 1989, General and comparative endocrinology.

[10]  J. Takahashi,et al.  Alpha-2 adrenergic regulation of melatonin release in chick pineal cell cultures , 1987, The Journal of neuroscience : the official journal of the Society for Neuroscience.

[11]  B. Lönnerdal,et al.  Compartmentalization and quantitation of protein in human milk. , 1987, The Journal of nutrition.

[12]  P. Cowen,et al.  Direct radioimmunoassay for melatonin in plasma. , 1983, Clinical chemistry.

[13]  R. Reiter,et al.  Tryptophan loading increases daytime serum melatonin levels in intact and pinealectomized rats. , 1993, Life sciences.

[14]  B. Poeggeler,et al.  Effect of tryptophan administration on circulating melatonin levels in chicks and rats: evidence for stimulation of melatonin synthesis and release in the gastrointestinal tract. , 1992, Life sciences.

[15]  M. Blum,et al.  Quantitation of Nuclear Low-Level Gene Expression in Central Nervous System Using Solution Hybridization and in Situ Hybridization , 1989 .