Dr Perry Barrett - Molecular mechanisms in body weight regulation
Contact details for Dr Perry Barrett
Telephone:+44 (0)1224 438660
The current research focuses on a physiological model of body weight regulation, the Siberian hamster. This animal very precisely regulates body weight by using the prevailing light period of the season of the year, having a higher body weight during spring and summer months and decreases body weight during autumn and winter. The change in body weight is almost entirely due to the accumulation or loss of fat. How does the hamster control the amount of fat it accumulates or loses? What lessons can we learn and apply to the human situation?
So far we have discovered a new region in the brain (which we have tentatively called the dmpARC) close to a site involved in signalling hunger or satiety (the arcuate nucleus), which responds to seasonal changes in photoperiod. We have seen major changes in gene expression in this brain region for genes encoding the histamine H3 receptor, VGF (a secreted protein) and others. The involvement of the histamine H3 receptor in seasonal body weight regulation is the subject of a collaborative study with researchers at the University of Nottingham. So is the dmpARC the site in the brain where seasonal regulation of body weight is determined? If so what components in the controlling neurons are the key ones and how are these regulated? These are questions that are being addressed through techniques such as laser capture microdissection, in situ hybridization and techniques to investigate gene function.
Herwig, A., Wilson, D., Logie, T., Boelen, A., Morgan, P.J., Mercer, J.G., Barrett, P. Photoperiod and acute energy deficits interact on components of the thyroid hormone system in hypothalamic tanycytes of the Siberian Hamster. American Journal of Physiology – Regulatory, Integrative and Comparative Physiology, 296 (5) May 2009 pp, R 1037 – R1315
Cottrell, E.C., Cripps, R.L., Duncan, J.S., Barrett, P., Mercer, J.G., Herwig, A., Ozanne, S., Developmental changes in hypothalamic leptin receptor: relationship with the postnatal leptin surge and energy balance neuropeptides in the postnatal rat. American Journal of Physiology, Regulatory, Integrative and Comparative Physiology, 296 (3) pp. R631-R639
Ebling, F.J.P., Barrett, P. The regulation of seasonal changes in food intake and body weight , Journal of Neuroendocrinology, 20(6) June 208. pp. 827-833
Audinot, V., Bonnaud, A., Grandcolas, L., Rodriguez, M., Nagel, N., Galizzi, J-P., Balik, A., Messager, S., Hazlerigg, D.G., Barrett, P., Delgrange, P., Boutin, J.A. “Molecular cloning and pharmacological characterization of rat melatonin MT1 and MT2 receptors. Biochemical Pharmacology, 75 (10) pp. 2007 - 2019
Barrett, P., Ebling, F.J.P., Schuhler, S., Wilson, D., Ross, A.W., Warner, A., Jethwa, P., Boelen, A.,Visser, T.J., Ozanne, D., Archer, Z.A., Mercer, J.G., Morgan, P.J. (2007). Hypothalamic thyroid hormone catabolism acts a a gatekeeper for the seasonal control of body weight and reproduction. Endocrinology, 148 (8), pp. 3608-3617
Jethwa, P.H., Warner, A., Nilaweera, K.N., Brameld, J.M., Keyte, J.W. Carter, W.G., Bolton, N., Bruggraber, M., Morgan. P.J., Barrett, P., Ebling, F.J.P. (2007). VGF-derived peptide, TLQP-21, regulates food intake and body weight in Siberian hamsters. Endocrinology, 148 (8) August pp. 4044-4055