1. Increased body weight in mice lacking mu-opioid receptors.
- Author
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Han W, Hata H, Imbe H, Liu QR, Takamatsu Y, Koizumi M, Murphy NP, Senba E, Uhl GR, Sora I, and Ikeda K
- Subjects
- Abietanes blood, Animals, Eating genetics, Glucose Tolerance Test methods, In Situ Hybridization methods, Mice, Mice, Inbred C57BL, Mice, Knockout, Neuropeptide Y genetics, Neuropeptide Y metabolism, RNA, Messenger metabolism, Receptors, Opioid, mu physiology, Time Factors, Up-Regulation genetics, Body Weight genetics, Receptors, Opioid, mu deficiency
- Abstract
Opioids have been suggested to affect feeding behaviour. To clarify the role of mu-opioid receptors in feeding, we measured several parameters relating to food intake in mu-opioid receptor knockout mice. Here, we show that the knockout mice had increased body weight in adulthood, although the intake amount of standard food was similar between the wild-type and knockout littermates. Serum markers for energy homeostasis were not significantly altered in the knockout mice. Hypothalamic neuropeptide Y mRNA, however, was higher in knockouts than in wild-type mice. Our results suggest that the up-regulated expression of neuropeptide Y mRNA might contribute to the increased weights of adult mu-opioid receptor knockout mice.
- Published
- 2006
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