title: Melatonin and pineal gland peptides are able to correct the impairment of reproductive cycles in rats.
abstract: Catecholamines play an important role in the hypothalamic regulation of the synthesis and secretion of gonadotropin- releasing hormone, or gonadoliberin. We have shown that melatonin and the pineal gland peptides (epithalamine and epitalon) exert a correcting influence on the diurnal dynamics of norepinephrine (NE) in the medial preoptic area (MPA) and of dopamine (DA) in the median eminence with arcuate nuclei (ME-Arc) disturbed by single administration of the neurotoxic xenobiotic 1,2-dimethylhydrazine (DMH) in female rats. It has been found that experiments with DMH administration can be used as an animal model of female reproductive system premature aging. The investigation of epithalamine (a polypeptide preparation from the bovine pineal gland) effect on circadian rhythms disturbed by the neurotoxic compound DMH has shown a recovery of the diurnal dynamics of NE in MPA. In addition, NE was found to decrease from 9:30 till 11 o'clock, Circadian Time (CT), which was typical of control animals. Epitalon (Ala-Glu-Asp-Gly) proved to be more effective in ME-Arc. This peptide prevents the xenobiotic caused disturbance of DA diurnal rhythm, keeping this metabolite low at 5 o'clock (CT) with it having increased by 11 o'clock (CT). The data obtained suggest that the pineal gland is important for the circadian signal normalization needed for gonadoliberin surge on the day of proestrus. Melatonin and peptides of the pineal gland can be considered as effective protectors of female reproductive system from xenobiotics and premature aging.
authors.affiliation: Laboratory of Perinatal Biochemistry, DO Ott Institute of Obstetrics and Gynecology, Russian Academy of Medical Sciences, St. Petersburg, Russia. arutjunyan@aa3703.spb.edu
authors.forename: Alexander
authors.initials: A
authors.lastname: Arutjunyan
authors.forename: Ljudmila
authors.initials: L
authors.lastname: Kozina
authors.forename: Yulia
authors.initials: Y
authors.lastname: Milyutina
authors.forename: Andrew
authors.initials: A
authors.lastname: Korenevsky
authors.forename: Michael
authors.initials: M
authors.lastname: Stepanov
authors.forename: Vladimir
authors.initials: V
authors.lastname: Arutyunov
mesh_terms: D019813:1,2-Dimethylhydrazine / Q000633:toxicity; D000367:Age Factors; D000375:Aging / Q000378:metabolism*; D019588:Aging, Premature; D000818:Animals; D002940:Circadian Rhythm / Q000187:drug effects*; D004298:Dopamine / Q000378:metabolism; D030762:Estrous Cycle / Q000187:drug effects / Q000378:metabolism; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism; D008550:Melatonin / Q000378:metabolism / Q000494:pharmacology*; D009638:Norepinephrine / Q000378:metabolism; D009842:Oligopeptides / Q000378:metabolism / Q000494:pharmacology*; D010455:Peptides / Q000378:metabolism / Q000494:pharmacology*; D010870:Pineal Gland / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012098:Reproduction / Q000187:drug effects*; D013997:Time Factors
chemical_list: D009842:Oligopeptides; D010455:Peptides; D007987:Gonadotropin-Releasing Hormone; C027437:epithalamin; D019813:1,2-Dimethylhydrazine; D008550:Melatonin; C421253:alanyl-glutamyl-aspartyl-glycine; D004298:Dopamine; D009638:Norepinephrine