This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Ribelayga, C. Articles by Simonneaux, V. Search for Related Content PubMed PubMed Citation Articles by Ribelayga, C. Articles by Simonneaux, V. Social Bookmarking                         What's this?

Photoperiodic Control of the Rat Pineal Arylalkylamine-N-Acetyltransferase and Hydroxyindole-O-Methyltransferase Gene Expression and Its Effect on Melatonin Synthesis

Marie-Laure Garidou

André Malan

François Gauer

Christiane Calgari

Paul Pévet

Valérie Simonneaux

Neurobiologie des Fonctions Rythmiques et Saisonnières, UMR-CNRS 7518, Université Louis Pasteur, 12, rue de l'Université, F-67000 Strasbourg, France

Photoperiodic changes of pineal melatonin (MEL) profile are accompanied by parallel changes of arylalkylamine-N-acetyltransferase (AA-NAT) activity. In the present study, the authors investigated, for the first time, whether two other important variables of pineal metabolism, AA-NAT and hydroxyindole-O-methyltransferase (HIOMT) gene expression, also may be affected by the photoperiod. Evening rises in AA-NAT and HIOMT mRNA and in circulating MEL occurred concomitantly with an increased delay from dark onset as scotophase shortened. On the opposite, the morning declines of all three variables occurred with different kinetics but were locked to light onset. These observations demonstrate that the daily rhythms in AA-NAT and HIOMT gene expression are modulated by the photoperiod and bring further evidence in favor of nor adrenaline as the possible link between the endogenous clock and MEL. Interestingly, the duration of the nocturnal peak in HIOMT mRNA was positively correlated with HIOMT activity. In conclusion, this study adds two important links to the chain of mechanisms involved in the photoperiodic control of pineal metabolism. First, photoperiodic modulation of the MEL rhythm primarily results from changes in the AA-NAT gene expression. Second, the photoperiodic regulation of HIOMT activity occurs at the transcriptional level.

Key Words: circadian rhythm • suprachiasmatic nucleus • hydroxyindole-O-methyltransferase • arylalkylamine-N-acetyltransferase • melatonin • pineal • photoperiodism

Journal of Biological Rhythms, Vol. 14, No. 2, 105-115 (1999)
DOI: 10.1177/074873099129000489


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				M.-L. Garidou, E. Diaz, C. Calgari, P. Pevet, and V. Simonneaux Transcription Factors May Frame Aa-nat Gene Expression and Melatonin Synthesis at Night in the Syrian Hamster Pineal Gland Endocrinology, June 1, 2003; 144(6): 2461 - 2472. [Abstract] [Full Text] [PDF]

				V. Simonneaux and C. Ribelayga Generation of the Melatonin Endocrine Message in Mammals: A Review of the Complex Regulation of Melatonin Synthesis by Norepinephrine, Peptides, and Other Pineal Transmitters Pharmacol. Rev., June 1, 2003; 55(2): 325 - 395. [Abstract] [Full Text] [PDF]

				M.-L. Garidou, B. Vivien-Roels, P. Pevet, J. Miguez, and V. Simonneaux Mechanisms regulating the marked seasonal variation in melatonin synthesis in the European hamster pineal gland Am J Physiol Regulatory Integrative Comp Physiol, April 1, 2003; 284(4): R1043 - R1052. [Abstract] [Full Text] [PDF]

				D. J. Kennaway, A. Voultsios, T. J. Varcoe, and R. W. Moyer Melatonin in mice: rhythms, response to light, adrenergic stimulation, and metabolism Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2002; 282(2): R358 - R365. [Abstract] [Full Text] [PDF]

				C. Ribelayga, P. Pevet, and V. Simonneaux HIOMT drives the photoperiodic changes in the amplitude of the melatonin peak of the Siberian hamster Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2000; 278(5): R1339 - R1345. [Abstract] [Full Text] [PDF]