title: Nasal oxytocin administration reduces food intake without affecting locomotor activity and glycemia with c-Fos induction in limited brain areas.
abstract: Recent studies have considered oxytocin (Oxt) as a possible medicine to treat obesity and hyperphagia. To find the effective and safe route for Oxt treatment, we compared the effects of its nasal and intraperitoneal (IP) administration on food intake, locomotor activity, and glucose tolerance in mice. Nasal Oxt administration decreased food intake without altering locomotor activity and increased the number of c-Fos-immunoreactive (ir) neurons in the paraventricular nucleus (PVN) of the hypothalamus, the area postrema (AP), and the dorsal motor nucleus of vagus (DMNV) of the medulla. IP Oxt administration decreased food intake and locomotor activity and increased the number of c-Fos-ir neurons not only in the PVN, AP, and DMNV but also in the nucleus of solitary tract of the medulla and in the arcuate nucleus of the hypothalamus. In IP glucose tolerance tests, IP Oxt injection attenuated the rise of blood glucose, whereas neither nasal nor intracerebroventricular Oxt affected blood glucose. In isolated islets, Oxt administration potentiated glucose-induced insulin secretion. These results indicate that both nasal and IP Oxt injections reduce food intake to a similar extent and increase the number of c-Fos-ir neurons in common brain regions. IP Oxt administration, in addition, activates broader brain regions, reduces locomotor activity, and affects glucose tolerance possibly by promoting insulin secretion from pancreatic islets. In comparison with IP administration, the nasal route of Oxt administration could exert a similar anorexigenic effect with a lesser effect on peripheral organs.
authors.affiliation: Division of Integrative Physiology, Department of Physiology, Jichi Medical University School of Medicine, Shimotsuke, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Maejima
authors.forename: Rauza Sukma
authors.initials: RS
authors.lastname: Rita
authors.forename: Putra
authors.initials: P
authors.lastname: Santoso
authors.forename: Masato
authors.initials: M
authors.lastname: Aoyama
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Hiraoka
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Nishimori
authors.forename: Darambazar
authors.initials: D
authors.lastname: Gantulga
authors.forename: Kenju
authors.initials: K
authors.lastname: Shimomura
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Yada
mesh_terms: D000281:Administration, Intranasal; D000818:Animals; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D004435:Eating / Q000187:drug effects*; D005951:Glucose Tolerance Test; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009043:Motor Activity / Q000187:drug effects; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D010121:Oxytocin / Q000008:administration & dosage*; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism
chemical_list: D001786:Blood Glucose; D016755:Proto-Oncogene Proteins c-jun; D010121:Oxytocin