title: Albutensin A and complement C3a decrease food intake in mice.
abstract: Albutensin A (Ala-Phe-Lys-Ala-Trp-Ala-Val-Ala-Arg) derived from serum albumin dose-dependently decreased food intake after intracerebroventricular (10-50 nmol/mouse) or peripheral (0.3-1.0 micromol/mouse) administration in fasted conscious ddY mice. Albutensin A delayed gastric emptying and elevated blood glucose levels. Although albutensin A showed low affinity for bombesin receptor, it decreased food intake in bombesin receptor knockout mice, indicating that its inhibitory effect on feeding was not mediated through bombesin receptor. Then, we investigated whether the albutensin A-induced decrease in food intake was mediated by complement C3a and C5a receptors, because albutensin A had affinities for these receptors. Des-Arg-albutensin A, lacking affinity for C3a and C5a receptors, did not inhibit food intake. We found for the first time that centrally administered C3a (10-100 pmol/mouse) by itself decreased food intake in fasted mice. In contrast, C5a increased food intake after central injection. Based on these results, we conclude that the inhibitory effect of albutensin A on food intake is mediated through the C3a receptor.
authors.affiliation: Division of Food Bioscience and Biotechnology, Graduate School of Agriculture, Kyoto University, Gokasho Uji, 611-0011, Kyoto, Japan.
authors.forename: Kousaku
authors.initials: K
authors.lastname: Ohinata
authors.forename: Akio
authors.initials: A
authors.lastname: Inui
authors.forename: Akihiro
authors.initials: A
authors.lastname: Asakawa
authors.forename: Keiji
authors.initials: K
authors.lastname: Wada
authors.forename: Etsuko
authors.initials: E
authors.lastname: Wada
authors.forename: Masaaki
authors.initials: M
authors.lastname: Yoshikawa
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology; D000818:Animals; D015703:Antigens, CD / Q000737:chemistry*; D001786:Blood Glucose / Q000378:metabolism; D015926:Complement C3a / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005247:Feeding Behavior; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D009842:Oligopeptides / Q000494:pharmacology*; D011485:Protein Binding; D044087:Receptor, Anaphylatoxin C5a; D018004:Receptors, Bombesin / Q000235:genetics; D011951:Receptors, Complement / Q000737:chemistry*; D013997:Time Factors
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D015703:Antigens, CD; D001786:Blood Glucose; D009842:Oligopeptides; D044087:Receptor, Anaphylatoxin C5a; D018004:Receptors, Bombesin; D011951:Receptors, Complement; C418002:albutensin A; D015926:Complement C3a