title: Norepinephrine-induced enlargement of nucleus in cultured myocardial cells.
abstract: The change in the nuclear size of neonatal rat myocardial cells was evaluated under the culture conditions of exposure to norepinephrine (NE). Daily administration for 1 week of 0.2, 2, and 20 ng/ml NE induced a significant increase in nuclear size as a result of the dose-dependent quality of the nuclei. NE also stimulated a beating response in the cultured myocardial cells because of this dose dependency. A good correlation was found between the two markers and the NE dose dependency. Single or mononucleated myocardial cells often appeared in the NE-treated groups. Ornithine decarboxylase activity was not acutely stimulated even by 20 ng/ml NE. These observations suggest that administration of NE induces nuclear enlargement and enhances nuclear function through the stimulation of beating. Further, there may not be a direct relation between nuclear enlargement and the polyamine synthesis pathways.
authors.affiliation: Department of Pathology, Shimane Medical University, Izumo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Igawa
authors.forename: Y
authors.initials: Y
authors.lastname: Yamori
authors.forename: L J
authors.initials: LJ
authors.lastname: Lewis
authors.forename: R C
authors.initials: RC
authors.lastname: Tarazi
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000187:drug effects*; D046508:Culture Techniques; D004305:Dose-Response Relationship, Drug; D009206:Myocardium / Q000648:ultrastructure*; D009638:Norepinephrine / Q000494:pharmacology*; D009955:Ornithine Decarboxylase / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D009955:Ornithine Decarboxylase; D009638:Norepinephrine