title: L-Ornithine intake affects sympathetic nerve outflows and reduces body weight and food intake in rats.
abstract: Ingesting the amino acid l-ornithine effectively improves lipid metabolism in humans, although it is unknown whether it affects the activities of autonomic nerves that supply the peripheral organs related to lipid metabolism, such as adipose tissues. Thus, we investigated the effects of l-ornithine ingestion on autonomic nerves that innervate adipose tissues and the feeding behaviors of rats. Intragastric injection of l-ornithine (2.5%) in urethane-anesthetized rats activated sympathetic nerve activity to white adipose tissue (WAT-SNA), and stimulated sympathetic nerve activity to brown adipose tissue (BAT-SNA). In addition, WAT-SNA responses to l-ornithine were abolished in rats with ablated abdominal vagal nerves. l-ornithine ingestion for 9 weeks also significantly reduced rats' body weight, food intake, and abdominal fat weight. Proopiomelanocortin (POMC) levels in the hypothalamus and uncoupling protein 1 (UCP1) levels in brown adipose tissue were significantly increased in rats that ingested 2.5% l-ornithine for 9 weeks. These results suggested that ingested l-ornithine was taken up in the gastrointestinal organs and stimulated afferent vagal nerves and activated the central nervous system. Subsequently, increased hypothalamic POMC activated sympathetic neurotransmission to adipose tissues and accelerated energy expenditure.
authors.affiliation: Department of Biomedical Sciences, College of Life Sciences, Ritsumeikan University, Kusatsu 525-8577, Shiga, Japan.
authors.forename: Yuuki
authors.initials: Y
authors.lastname: Konishi
authors.affiliation: Department of Biomedical Sciences, College of Life Sciences, Ritsumeikan University, Kusatsu 525-8577, Shiga, Japan.
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Koosaka
authors.affiliation: Department of Biomedical Sciences, College of Life Sciences, Ritsumeikan University, Kusatsu 525-8577, Shiga, Japan.
authors.forename: Ryuutaro
authors.initials: R
authors.lastname: Maruyama
authors.affiliation: Department of Biomedical Sciences, College of Life Sciences, Ritsumeikan University, Kusatsu 525-8577, Shiga, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Imanishi
authors.affiliation: Department of Biomedical Sciences, College of Life Sciences, Ritsumeikan University, Kusatsu 525-8577, Shiga, Japan.
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Kasahara
authors.affiliation: Department of Biomedical Sciences, College of Life Sciences, Ritsumeikan University, Kusatsu 525-8577, Shiga, Japan.
authors.forename: Ai
authors.initials: A
authors.lastname: Matsuda
authors.affiliation: Healthcare Products Development Center, Kyowa Hakko Bio Co., Ltd., Tsukuba 305-0841, Ibaraki, Japan.
authors.forename: Saori
authors.initials: S
authors.lastname: Akiduki
authors.affiliation: Healthcare Products Development Center, Kyowa Hakko Bio Co., Ltd., Tsukuba 305-0841, Ibaraki, Japan.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Hishida
authors.affiliation: Department of Physiology II, Kanazawa Medical University, Uchinada 920-0293, Ishikawa, Japan.
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Kurata
authors.affiliation: Department of Physiology II, Kanazawa Medical University, Uchinada 920-0293, Ishikawa, Japan.
authors.forename: Toshishige
authors.initials: T
authors.lastname: Shibamoto
authors.affiliation: Department of Biomedical Sciences, College of Life Sciences, Ritsumeikan University, Kusatsu 525-8577, Shiga, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Satomi
authors.affiliation: Department of Biomedical Sciences, College of Life Sciences, Ritsumeikan University, Kusatsu 525-8577, Shiga, Japan; Department of Physiology II, Kanazawa Medical University, Uchinada 920-0293, Ishikawa, Japan. Electronic address: mtanida@kanazawa-med.ac.jp.
authors.forename: Mamoru
authors.initials: M
authors.lastname: Tanida
mesh_terms: D002001:Adipose Tissue, Brown / Q000187:drug effects / Q000294:innervation / Q000378:metabolism; D052436:Adipose Tissue, White / Q000187:drug effects / Q000294:innervation; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D004435:Eating / Q000187:drug effects; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism; D007473:Ion Channels / Q000378:metabolism; D008297:Male; D024101:Mitochondrial Proteins / Q000378:metabolism; D009952:Ornithine / Q000008:administration & dosage*; D011333:Pro-Opiomelanocortin / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013564:Sympathetic Nervous System / Q000187:drug effects* / Q000502:physiology*; D000071256:Uncoupling Protein 1
chemical_list: D007473:Ion Channels; D024101:Mitochondrial Proteins; C000604371:UCP1 protein, human; C000604373:Ucp1 protein, rat; D000071256:Uncoupling Protein 1; D011333:Pro-Opiomelanocortin; D009952:Ornithine
keywords: Adipose tissue; Afferent vagal nerve; Appetite; Autonomic nervous system; Electrophysiology; Hypothalamus