Tanida Mamoru, Niijima Akira, Shen Jiao, Nakamura Takuo, Nagai Katsuya
Division of Protein Metabolism, Institute for Protein Research, Osaka University, Suita, Osaka, Japan.
Brain Res. 2005 Oct 5;1058(1-2):44-55. doi: 10.1016/j.brainres.2005.07.048.
Previously, we observed that olfactory stimulation with scent of grapefruit oil (SGFO) enhances sympathetic nerve activities and suppresses gastric vagal (parasympathetic) nerve activity (GVNA), increases plasma glycerol concentration and body temperature, and decreases appetite in rats. Here, we show that olfactory stimulation with SGFO for 10 min elevates renal sympathetic nerve activity (RSNA) and blood pressure (BP) and lowers GVNA in urethane-anesthetized rats. Olfactory stimulation with limonene, a major component of grapefruit oil, also elicited increases in RSNA and BP in urethane-anesthetized rats. Anosmic treatment with ZnSO(4) eliminated both the effects of SGFO and scent of limonene on RSNA and BP. Intracerebral administration of diphenhydramine, a histaminergic H1-antagonist, abolished SGFO- or scent of limonene-mediated increases in RSNA and BP as well as the decrease in GVNA. Moreover, bilateral lesions of the hypothalamic suprachiasmatic nucleus (SCN) eliminated the SGFO- and limonene-mediated increases in RSNA and BP and decrease in GVNA, but bilateral lesions of the cerebral cortex did not have any affect on these parameters. These findings suggest that scent of grapefruit oil and its active component, limonene, affect autonomic neurotransmission and blood pressure through central histaminergic nerves and the suprachiasmatic nucleus.
此前，我们观察到用葡萄柚油气味（SGFO）进行嗅觉刺激可增强大鼠的交感神经活动并抑制胃迷走神经（副交感神经）活动（GVNA），增加血浆甘油浓度和体温，并降低大鼠的食欲。在此，我们表明，在氨基甲酸乙酯麻醉的大鼠中，用SGFO进行10分钟的嗅觉刺激可提高肾交感神经活动（RSNA）和血压（BP），并降低GVNA。用葡萄柚油的主要成分柠檬烯进行嗅觉刺激，也可使氨基甲酸乙酯麻醉的大鼠的RSNA和BP升高。用硫酸锌进行嗅觉缺失处理可消除SGFO和柠檬烯气味对RSNA和BP的影响。脑内注射组胺能H1拮抗剂苯海拉明可消除SGFO或柠檬烯气味介导的RSNA和BP升高以及GVNA降低。此外，下丘脑视交叉上核（SCN）的双侧损伤可消除SGFO和柠檬烯介导的RSNA和BP升高以及GVNA降低，但大脑皮层的双侧损伤对这些参数没有任何影响。这些发现表明，葡萄柚油气味及其活性成分柠檬烯通过中枢组胺能神经和视交叉上核影响自主神经传递和血压。
