title: Labeled [³H]--thymidine incorporation in the DNA of 3T3-L1 preadipocytes due to MT₂- and not MT₃- melatonin receptor.
abstract: The discovery of MT₁, MT₂, and MT₃ melatonin receptors on adipose tissue cells gives grounds for considering the possibility of melatonin as a factor which influences energy storage through modulation of metabolism and adipocyte proliferation. To date only a few contradictory studies have been published on the influence of melatonin on preadipocytes. The aim of the present study is to evaluate the influence of melatonin at physiological and supraphysiological concentrations on the proliferation of 3T3-L1 murine preadipocytes after 3 and 24 hours of the experiment and to determine the participation of membrane melatonin MT₂ receptors, and for the first time--MT₃, in its melatonin action during a 24-hour experiment. The 3T3-L1 murine preadipocyte cell line were cultured with or without melatonin at 10⁻³ and 10⁻⁹ mol/L, with or without melatonin antagonists luzindole (10⁻⁴ mol/L) and prazosin (10⁻⁵ mol/L). Cell proliferation was determined by means of labeled [³H]-thymidine incorporation in the DNA of the cell. Melatonin at both physiological and supraphysiological concentrations has a stimulating effect on the number of 3T3-L1 preadipocytes. The application of luzindole inhibits the above effect of melatonin both at 10⁻³ mol/L and 10⁻⁹ mol/L concentrations (P<0.05). The presence of prazosin does not have a statistically significant influence on the effects of melatonin action. Summarizing, it has been proven that melatonin exerts a proproliferative effect on 3T3-L1 preadipocytes at physiological and supraphysiological concentrations, partially by MT₂, and not by MT₃ receptors.
authors.affiliation: Department of Neurology in Zabrze, Medical University of Silesia, Poland. m.adamczyk.sowa@gmail.com.
authors.forename: M
authors.initials: M
authors.lastname: Adamczyk-Sowa
authors.forename: P
authors.initials: P
authors.lastname: Sowa
authors.forename: K
authors.initials: K
authors.lastname: Zwirska-Korczala
authors.forename: K
authors.initials: K
authors.lastname: Pierzchala
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D004247:DNA / Q000378:metabolism*; D008550:Melatonin / Q000494:pharmacology*; D051379:Mice; D011224:Prazosin / Q000494:pharmacology; D044123:Receptor, Melatonin, MT2 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D044094:Receptors, Melatonin / Q000037:antagonists & inhibitors / Q000378:metabolism; D013936:Thymidine / Q000378:metabolism*; D014363:Tryptamines / Q000494:pharmacology
chemical_list: D044123:Receptor, Melatonin, MT2; D044094:Receptors, Melatonin; D014363:Tryptamines; C057154:luzindole; D004247:DNA; D008550:Melatonin; D013936:Thymidine; D011224:Prazosin