UCP1 is present in porcine adipose tissue and is responsive to postnatal leptin

    1. Latifa Abdennebi-Najar
    1. UP 2012.10.101 EGEAL, Institut Polytechnique LaSalle, Beauvais, France
      1School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, LE12 5RD Nottingham, UK
      2INRA UMR 703, Ecole Nationale Vétérinaire, Nantes, France
      3INRA, UMR1198 BDR Biologie du Développement et Reproduction, Jouy-en-Josas, France
      4Unité de Recherche 04UR08/03, Faculté de Médecine, Tunis, Tunisia
      5The Hebrew University of Jerusalem, PO Box 12, Rehovot 76100, Israel
      6Unité NOPA, INRA, Centre de recherche Jouy en Josas, Jouy-en-Josas, France
      7Early Life Research Unit, Academic Child Health, School of Medicine, University Hospital, The University of Nottingham, Nottingham NG7 2UH, UK
    1. Correspondence should be addressed to L Abdennebi-Najar; Email: latifa.najar{at}lasalle-beauvais.fr


    Intrauterine growth restriction (IUGR) may be accompanied by inadequate thermoregulation, especially in piglets that are not considered to possess any brown adipose tissue (BAT) and are thus entirely dependent on shivering thermogenesis in order to maintain body temperature after birth. Leptin can stimulate heat production by promoting non-shivering thermogenesis in BAT, but whether this response occurs in piglets is unknown. Newborn female piglets that were characterised as showing IUGR (mean birth weight of approximately 0.98 kg) were therefore administered injections of either saline or leptin once a day for the first 5 days of neonatal life. The dose of leptin was 0.5 mg/kg, which is sufficient to increase plasma leptin by approximately tenfold and on the day of birth induced a rapid increase in body temperature to values similar to those of normal-sized ‘control’ piglets (mean birth weight of ∼1.47 kg). Perirenal adipose tissue was then sampled from all offspring at 21 days of age and the presence of the BAT-specific uncoupling protein 1 (UCP1) was determined by immunohistochemistry and immunoblotting. UCP1 was clearly detectable in all samples analysed and its abundance was significantly reduced in the IUGR piglets that had received saline compared with controls, but was raised to the same amount as in controls in those IUGR females given leptin. There were no differences in gene expression between primary markers of brown and white adipose tissues between groups. In conclusion, piglets possess BAT that when stimulated exogenously by leptin can promote increased body temperature.

    • Received in final form 4 August 2014
    • Accepted 12 August 2014
    • Made available online as an Accepted Preprint 13 August 2014
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