title: PNMT transgenic mice have an aggressive phenotype.
abstract: PNMT (phenylethanolamine-N-methyl-transferase) is the enzyme that catalyzes the formation of epinephrine from norepinephrine. In transgenic mice over-expressing PNMT, observations revealed a very high level of aggression compared to their background strain, C57BL/6J. To evaluate the influence of PNMT on aggression and emotionality in this transgenic line, single-sex male and female groups were independently established that consisted of either four wild-type mice or four transgenic mice overexpressing PNMT. The members of each group were littermates. Mixed single-sex groups consisting of two transgenic mice and two wild-type mice were also established. Almost no fights were observed within the female groups. In males, the transgenic line showed a significantly higher level of fighting than controls (p=0.007) and mixed male groups (p=0.02). Housing mice from the transgenic line in mixed groups with wild-type mice seems to decrease the level of aggression in the transgenic line. In conclusion, this is the first study to demonstrate a clear, significant increase in aggression arising from PNMT overexpression. This suggests an important role for central epinephrine levels in aggressive behavior.
authors.affiliation: The Royal Veterinary and Agricultural University of Copenhagen, Division of Laboratory Animal Science and Welfare, Department of Veterinary Pathobiology, Frederiksberg, Denmark. dobj@kvl.dk
authors.forename: D B
authors.initials: DB
authors.lastname: Sørensen
authors.forename: P F
authors.initials: PF
authors.lastname: Johnsen
authors.forename: B M
authors.initials: BM
authors.lastname: Bibby
authors.forename: A
authors.initials: A
authors.lastname: Böttner
authors.forename: S R
authors.initials: SR
authors.lastname: Bornstein
authors.forename: G
authors.initials: G
authors.lastname: Eisenhofer
authors.forename: K
authors.initials: K
authors.lastname: Pacak
authors.forename: A K
authors.initials: AK
authors.lastname: Hansen
mesh_terms: D000374:Aggression / Q000502:physiology*; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D001921:Brain / Q000201:enzymology; D004837:Epinephrine / Q000378:metabolism; D005106:Exploratory Behavior / Q000502:physiology; D005260:Female; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D010641:Phenotype; D010625:Phenylethanolamine N-Methyltransferase / Q000235:genetics* / Q000378:metabolism*
chemical_list: D010625:Phenylethanolamine N-Methyltransferase; D004837:Epinephrine