Horm Metab Res 2005; 37(3): 159-163
DOI: 10.1055/s-2005-861301
Original Clinical
© Georg Thieme Verlag KG Stuttgart · New York

PNMT Transgenic Mice Have an Aggressive Phenotype

D.  B.  Sørensen1 , P.  F.  Johnsen1 , B.  M.  Bibby2 , A.  Böttner3 , S.  R.  Bornstein4 , G.  Eisenhofer5 , K.  Pacak6 , A.  K.  Hansen1
  • 1The Royal Veterinary and Agricultural University of Copenhagen, Division of Laboratory Animal Science and Welfare, Department of Veterinary Pathobiology, Frederiksberg, Denmark
  • 2The Royal Veterinary and Agricultural University of Copenhagen, Department of Mathematics and Physics, Frederiksberg, Denmark
  • 3University Hospital for Children and Adolescents, University of Leipzig, Germany
  • 4University of Dresden Department of Medicine III, Dresden, Germany
  • 5Clinical Neurocardiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
  • 6Pediatric and Reproductive Endocrinology Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
Further Information

Publication History

Received 16 June 2004

Accepted after revision 7 October 2004

Publication Date:
12 April 2005 (online)

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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.