title: The effects of orexins on monoaminerg-induced changes in vasopressin level in rat neurohypophyseal cell cultures.
abstract: The effects of orexin-monoaminergic compound interactions on vasopressin release were studied in 14-day neurohypophyseal cell cultures from adult rats, prepared by an enzymatic dissociation technique. The vasopressin contents of the supernatants were determined by radioimmunoassay. Following administration of either orexin-A or orexin-B in increasing doses, significant changes were not observed in the vasopressin levels of the supernatant media. The vasopressin level substantially increased after epinephrine, norepinephrine, serotonin, histamine, dopamine or K(+) treatment. Preincubation with either orexin-A or orexin-B reduced the epinephrine-, histamine- or serotonin-induced increases in vasopressin level, but the vasopressin concentrations of the supernatant media remained above the control level. There was no significant difference in decreasing effect between orexin-A and orexin-B. Neither orexin-A nor orexin-B induced changes in vasopressin release following monoaminergic compound treatment. The results indicate that the changes in vasopressin secretion induced by the monoaminergic system can be directly influenced by orexin system. It may be presumed that the orexins can play a physiological role in the regulation of the water metabolism by reducing the effect of increased vasopressin release caused by monoaminergic compounds. The interactions between the monoaminergic and orexin systems regarding vasopressin secretion occur at both the hypothalamic and the neurohypophyseal level.
authors: Department of Physiology, Anatomy and Neurosciences, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary.
authors: Gyöngyi K
authors: GK
authors: Kis
authors: Tímea
authors: T
authors: Ocskó
authors: Márta
authors: M
authors: Gálfi
authors: Marianna
authors: M
authors: Radács
authors: Zsolt
authors: Z
authors: Molnár
authors: Kinga
authors: K
authors: Rákosi
authors: Andor H
authors: AH
authors: Molnár
authors: Ferenc
authors: F
authors: László
authors: Csaba
authors: C
authors: Varga
authors: Ferenc A
authors: FA
authors: László
mesh_terms: D000818:Animals; D015306:Biogenic Monoamines / Q000494:pharmacology*; D002478:Cells, Cultured; D004298:Dopamine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004837:Epinephrine / Q000494:pharmacology; D006632:Histamine / Q000494:pharmacology; D047908:Intracellular Signaling Peptides and Proteins / Q000494:pharmacology*; D008297:Male; D009479:Neuropeptides / Q000494:pharmacology*; D009638:Norepinephrine / Q000494:pharmacology; D000068797:Orexins; D010904:Pituitary Gland, Posterior / Q000166:cytology* / Q000187:drug effects*; D011188:Potassium / Q000494:pharmacology; D011863:Radioimmunoassay; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000494:pharmacology; D014667:Vasopressins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D015306:Biogenic Monoamines; D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins; D014667:Vasopressins; D012701:Serotonin; D006632:Histamine; D011188:Potassium; D004298:Dopamine; D009638:Norepinephrine; D004837:Epinephrine