title: Effect of an intraduodenal injection of fat on the activities of the adrenal efferent sympathetic nerve and the gastric efferent parasympathetic nerve in urethane-anesthetized rats.
abstract: Nutrient information from the gastrointestinal tract to the brain plays a critical role in the regulation of appetite and energy homeostasis. The autonomic nervous system controls the functions of several tissues to regulate the energy homeostasis of the whole body. Autonomic nerve activity is influenced by environmental or exogenous changes in even a single tissue. In the present study, we investigated the effect of an intraduodenal injection of fat on the activities of the autonomic nerves innervating the adrenal gland and stomach in urethane-anesthetized rats. An intraduodenal injection of corn oil suppressed adrenal efferent sympathetic nerve activity (ASNA) and stimulated gastric efferent vagal nerve activity (GVNA). A lipase inhibitor, epsilon-polylysine, coinjected with corn oil completely suppressed the corn oil-induced changes in ASNA and GVNA. Further, an intraduodenal injection of fatty acid (linoleic acid) moderately suppressed ASNA and significantly stimulated GVNA; these results indicate that fat may affect autonomic nerve activity partly through the chemoreception of free fatty acids (FFAs), which are produced during the hydrolysis of fat (corn oil) by a pancreatic lipase, in the intestinal lumen. Furthermore, an intraduodenal injection of an intravenous fat emulsion with the same pH and osmotic pressure as the body fluid affected ASNA and GVNA in a similar manner as corn oil. These results suggest that intraduodenal fat suppresses ASNA and stimulates GVNA partly via the chemoreception of FFAs-the degradation products of fats-in the intestinal lumen.
authors.affiliation: Laboratory of Nutrition Chemistry, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan. sigenobu@kais.kyoto-u.ac.jp
authors.forename: Shigenobu
authors.initials: S
authors.lastname: Matsumura
authors.forename: Ai
authors.initials: A
authors.lastname: Eguchi
authors.forename: Nobuhide
authors.initials: N
authors.lastname: Kitabayashi
authors.forename: Mamoru
authors.initials: M
authors.lastname: Tanida
authors.forename: Jiao
authors.initials: J
authors.lastname: Shen
authors.forename: Yuko
authors.initials: Y
authors.lastname: Horii
authors.forename: Katsuya
authors.initials: K
authors.lastname: Nagai
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tsuzuki
authors.forename: Kazuo
authors.initials: K
authors.lastname: Inoue
authors.forename: Tohru
authors.initials: T
authors.lastname: Fushiki
mesh_terms: D000311:Adrenal Glands / Q000294:innervation*; D000758:Anesthesia; D018686:Anesthetics, Intravenous; D000818:Animals; D004041:Dietary Fats / Q000008:administration & dosage* / Q000494:pharmacology*; D004386:Duodenum / Q000502:physiology*; D004525:Efferent Pathways / Q000187:drug effects*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005217:Fat Emulsions, Intravenous / Q000494:pharmacology; D005227:Fatty Acids / Q000008:administration & dosage / Q000494:pharmacology; D005230:Fatty Acids, Nonesterified / Q000097:blood; D007202:Indicators and Reagents; D007267:Injections; D008049:Lipase / Q000037:antagonists & inhibitors; D008297:Male; D010275:Parasympathetic Nervous System / Q000187:drug effects*; D011107:Polylysine / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013270:Stomach / Q000294:innervation*; D013564:Sympathetic Nervous System / Q000187:drug effects*; D014520:Urethane
chemical_list: D018686:Anesthetics, Intravenous; D004041:Dietary Fats; D004791:Enzyme Inhibitors; D005217:Fat Emulsions, Intravenous; D005227:Fatty Acids; D005230:Fatty Acids, Nonesterified; D007202:Indicators and Reagents; D011107:Polylysine; D014520:Urethane; D008049:Lipase