Visualization of Activated BAT in Mice, with FDG-PET and Its Relation to UCP1

Christian Jeanguillaume, Gilles Metrard, Daniel Ricquier, Pierre Legras, Francis Bouchet, Franck Lacoeuille, François Hindre, Olivier Morel, Hervé Rakotonirina

LISA ISTIA, Université d’Angers, Angers, France.
Service Commun d’Animalerie Hospitalo, Universitaire (SCAHU), Angers, France.
Service de Médecine Nucléaire, CHR d’Orleans, Orleans, France.
Service de Médecine Nucléaire, CHU d’Angers, Angers, France.
Service de Médecine Nucléaire, ICO, Paul Papin, Angers, France.
Unité Inserm U646, Angers, France.
Université Paris Descartes, Institut Cochin, Paris, France.

DOI: 10.4236/ami.2013.33004                

Abstract

The visualization of symmetric structure by [₁₈F]-FluoroDeoxyGlucose-Positron Emission Tomography (FDG-PET), corresponding to adipose density in computed tomography (CT), has led to the idea that Brown Adipose Tissue (BAT) could be present in adult human. This article studies the FDG uptake in a mice model deficient on Uncoupling Protein 1 (UCP1), in a simple thermal activation protocol. Methods: FDG were injected in mice, control and knock out (K.O.) for the UCP1. Before imaging mice were placed either in cold or warm environment. BAT uptake was evaluated by ratio named RISC. Results: In warm condition, mean value of the Ratio of Inter-Scapular uptake (RISC) was 1.34 +/﹣ 0.27. After cold exposure, RISC increased 2 fold for control mice, male K.O. did not increase their RISC, female K.O. increased their RISC up to 2.45. Conclusion: Our study brought a further confirmation that FDG-PET visualised activated Brown Adipose Tissue. It gives a direct proof of the role of UCP1 in this process. The FDG uptake by cold female K.O. mice was unexpected.

Keywords

FDG; PET; Brown Adipose Tissue; Uncoupling Protein 1; Mice

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	K. Gessner, “Conradi Gesneri Medici Tigurine Historiae Animalium: Lib. I De Quadrupedibus Viviparis,” 1551.
[2]	Afzelius, “Brown Adipose Tissue: Its Gross Anatomy, Histology and Cytology,” In: O. Lindberg, Ed., Brown Adipose Tissue, Elsevier, New York, 1970, pp. 1-28.
[3]	D. G. Nicholls and E. Rial, “A History of the First Uncoupling Protein, UCP1,” Journal of Bioenergetics and Biomembranes, Vol. 31, No. 5, 1999, pp. 399-406.
[4]	D. Ricquier and F. Bouillaud, “Mitochondrial Uncoupling Proteins: From Mitochondria to the Regulation of Energy Balance,” The Journal of Physiology, Vol. 529, No. 1, 2000, pp. 3-10. doi:10.1111/j.1469-7793.2000.00003.x
[5]	B. Canon and J. Nedergaard, “Brown Adipose Tissue: Function and Physiological Significance,” Physiological Reviews, Vol. 84, No. 1, 2003, pp. 277-359. doi:10.1152/physrev.00015.2003
[6]	T. F. Hany, E. Gharehpapagh, E. M. Kamel, A. Buck, J. Himms-Hagen and G. K. von Schulthess, “Brown Adipose Tissue: A Factor to Consider in Symmetrical Tracer Uptake in the Neck and Upper Chest Region,” European Journal of Nuclear Medicine and Molecular Imaging, Vol. 29, No. 10, 2002, pp. 1393-1401. doi:10.1007/s00259-002-0902-6
[7]	A. M. Cypess, M. M. Sanaz Lehman, M. B. Gethin Williams, et al. “Identification and Importance of Brown Adipose Tissue in Adult Humans,” The New England Journal of Medicine, Vol. 360, No. 15, 2009, pp. 1509-1517. doi:10.1056/NEJMoa0810780
[8]	D. W. Van Marken Lichtenbelt, J. W. Vanhommerig, N. M. Smulders, et al. “Cold-Activated Brown Adipose Tissue in Healthy Men,” The New England Journal of Medicine, Vol. 360, No. 15, 2009, pp. 1500-1508. doi:10.1056/NEJMoa0808718
[9]	S. Enerback, A. Jacobsson, E. M. Simpson, C. Guerra, H. Yamashita, M. E. Harper, et al. “Mice Lacking Mitochondrial Uncoupling Protein Are Cold-Sensitive But Not Obese,” Nature, Vol. 387, No. 6628, 1997, p. 90. doi:10.1038/387090a0
[10]	V. Ouellet, S. M. Labbé, D. P. Blondin, S. Phoenix, B. Guérin, F. Haman, E. E. Turcotte, D. Richard and A. C. Carpentier, “Brown Adipose Tissue Oxidative Metabolism Contributes to Energy Expenditure during Acute Cold Exposure in Humans,” Journal of Clinical Investigation, Vol. 122, No. 2, 2012, pp. 545-552.