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.
Neurosci Res. 2010 Jul;67(3):236-44. doi: 10.1016/j.neures.2010.03.010. Epub 2010 Mar 31.
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.
从胃肠道到大脑的营养信息在调节食欲和能量平衡方面起着至关重要的作用。自主神经系统控制着几个组织的功能，以调节全身的能量平衡。自主神经活动会受到单个组织中外源或环境变化的影响。在本研究中，我们研究了十二指肠内注射脂肪对在体麻醉大鼠肾上腺和胃传出自主神经活动的影响。十二指肠内注射玉米油抑制肾上腺传出交感神经活动（ASNA）并刺激胃传出迷走神经活动（GVNA）。与玉米油共注射的脂肪酶抑制剂 epsilon-聚赖氨酸完全抑制了玉米油诱导的 ASNA 和 GVNA 的变化。此外，十二指肠内注射脂肪酸（亚油酸）适度抑制 ASNA 并显著刺激 GVNA；这些结果表明，脂肪可能部分通过在肠腔中由胰腺脂肪酶水解脂肪（玉米油）产生的游离脂肪酸（FFAs）的化学感受来影响自主神经活动。此外，与体液具有相同 pH 值和渗透压的静脉内脂肪乳剂的十二指肠内注射以类似于玉米油的方式影响 ASNA 和 GVNA。这些结果表明，十二指肠内脂肪通过肠腔中脂肪（玉米油）降解产物 FFAs 的化学感受部分抑制 ASNA 并刺激 GVNA。
