EFFECT OF TASTE & TRIGEMINAL STIMULATION ON NEUROENDOCRINE VALUES

目的：本研究的目的是确定味觉和/或三叉神经刺激是否对人类的神经内分泌水平有生理影响。我们在本研究中测试的假设是，苦味物质或碳酸化通过刺激三叉神经或味觉刺激改变血液中的应激激素水平。如果发生这种刺激，可能会对消瘦患者产生不良影响。不幸的是，许多患者服用的药物，例如艾滋病患者，非常苦，可能会引起三叉神经/味觉刺激，从而增加应激激素，并可能增加代谢率和消耗。正在研究的神经内分泌参数是肾上腺素、去甲肾上腺素和皮质醇。在摄食行为期间发生的味觉和嗅觉受体的化学感觉刺激促使头相反应，其包括唾液分泌和胃分泌增加、胰腺外分泌增加、胰岛素分泌增加和FFA血液水平降低。碳酸化（如碳酸饮料）虽然不被认为是一种味道，但会刺激三叉神经。苦味物质也可以通过渗透穿过味觉细胞的双脂膜以及细胞之间的紧密连接来刺激三叉神经，从而刺激游离神经末梢。方法：在这项研究中，受试者在30分钟的会议中进行筛选，并在筛选后至少一天进行一次4 1/2小时的会议。采集病史和饮食史，并在筛选时签署知情同意书。在测试日的上午，受试者入住CRU。然后将盐水锁置于受试者的外周手臂静脉中。60分钟后，采集基线血样。然后将10毫升的水喷入受试者的口中，受试者发出嘶嘶声并吐出。在刺激施用后5分钟、10分钟和25分钟采集血液样品。每个测试刺激之间有25分钟的休息时间。然后以与对照刺激物（水）相同的方式测试三种测试刺激物，并且在施用刺激物之前即刻和之后5、10和25分钟抽取血液。味觉刺激以固定的顺序传递，从最小到最强烈：水，碳酸水，苦味水（Invirase）和辣椒素。 分析每个血液样品的肾上腺素、去甲肾上腺素和皮质醇的血液浓度。每例受试者共抽取16次血液，每次抽取5 ml（每例受试者共抽取80 ml）。将血液离心，并将血浆冷冻在-70 ° C下直至测定。皮质醇通过放射免疫测定法测量，并且儿茶酚胺通过HPLC分离并电化学定量。受试者的脉搏和血压在刺激施用之前立即测量，并且在刺激施用之后25分钟测量。受试者对刺激的整体强度和每种刺激的愉快程度以及他们的情绪、警觉性和饥饿程度进行在线评分。在给予每种味觉刺激之前和之后比较肾上腺素、去甲肾上腺素和皮质醇的水平。结果：研究正在进行中。已对8名受试者进行了检测，但尚未对血浆样本进行分析。未来计划：这项检测最终将扩大到艾滋病患者和老年人。

Purpose: The purpose of this study is to determine whether taste and/or trigeminal stimulation have a physiological effect on neuroendocrine levels in humans. The hypothesis we are testing in the present study is that bitter substances or carbonation alter the level of stress hormones in the blood through stimulation of trigeminal or taste stimulation. If this stimulation occurs, it could have adverse effects in patients with wasting. Unfortunately, many of the medications taken by patients, for example those with AIDS, are extremely bitter, and could cause trigeminal/taste stimulation that could increase stress hormones, and possibly metabolic rate and wasting. The neuroendocrine parameters being studied are epinephrine, norepinephrine, and cortisol. Chemosensory stimulation of the taste and smell receptors, which occurs during ingestive behavior, prompts cephalic phase responses which include increased salivation and gastric secretion, increased pancreatic exocrine secretion, increased secretion of insulin, and decreased blood levels of FFA. Carbonation (as in carbonated beverages), while not considered a taste, stimulates the trigeminal nerve. Bitter substances can also stimulate the trigeminal nerve by permeating through bilipid membranes of taste cells as well tight junctions between cells to stimulate free nerve endings. Methods: In this study subjects are screened in a 30-minute session and tested in one 4 1/2 hour session at least one day after the screening. Medical and dietary histories are taken and informed consents are signed at the screening. In the morning of the test session day, the subject is admitted to the CRU. The subject then has a saline lock placed in a peripheral arm vein. Sixty minutes later a baseline blood sample is taken. Then 10 ml of water is squirted into the subject's mouth, which he swishes and expectorates. Blood samples are taken at 5 minutes, 10 minutes, and 25 minutes after stimulus administration. There is a twenty-five minute break between each test stimulus. Three test stimuli are then tested in the same manner as the control stimulus (water) and blood draws are taken immediately before, and 5, 10, and 25 minutes after administration of the stimulus. The taste stimuli are delivered in a fixed order, from least to most intense: water, carbonated water, bitter water (Invirase), and capsaicin. The blood concentrations of epinephrine, norepinephrine, and cortisol are analyzed for each blood sample. Each subject has a total of 16 blood draws of 5 ml each (80 ml total per subject). Blood is centrifuged and the plasma is frozen at -70oC until assay. Cortisol is measured by radioimmunoassay, and catecholamines are separated by HPLC and quantitated electrochemically. The subject's pulse and blood pressure is taken immediately before stimulus administration, and 25 minutes after stimulus administration. Subjects rate the perceived overall intensity of the stimulus and the pleasantness of each stimulus, as well as their mood, alertness, and level of hunger on line scales. The levels of epinephrine, norepinephrine, and cortisol are compared before and after the administration of each taste stimulation. Results: The study is in progress. Eight subjects have been tested but plasma samples have not yet been analyzed. Future plans: The testing will ultimately be expanded to AIDS patients and the elderly.