The role of salivary proteins in taste and feeding

唾液蛋白在味觉和进食中的作用

• 批准号: 8368159
• 负责人: Ann-Marie Torregrossa
• 金额: $ 13.95万
• 依托单位: FLORIDA STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2015-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8368159
• 关键词: Adult; Altered Taste; Animals; Attention; Basic Science; Binding; Broccoli - dietary; Child; Childhood; Chromosomes; Chromosomes, Human, Pair 5; Clinical Research; Consumption; Custom; Cycloheximide; Data; Detection; Diet; Eating; Exposure to; Foliate Papilla; Food; Food Selections; Funding Mechanisms; Genes; Genetic Variation; Gland; Goals; Health; Human; Intestines; Lead; Ligand Binding; Link; Medicine; Methods; Mind; Molecular; Mus; Oral; Parotid Gland; Perception; Pharmaceutical Preparations; Phytochemical; Plants; Play; Poison; Population; Production; Property; Protein Binding; Proteins; Psychophysiology; Quinine; Rattus; Research; Role; Saliva; Salivary; Salivary Proteins; Scientist; Series; Side; Signal Transduction; Site; Solutions; Source; Spinach - dietary; Staging; Stimulus; Stomach; Tannic Acid; Taste Perception; Testing; Variant; Work; career; design; drinking; feeding; nutrition; prevent; proline-rich proteins; receptor; research study; response; salivary proline-rich proteins; sucrose octaacetate

DESCRIPTION (provided by applicant): Variation in bitter taste perception may play a key role in diet selection, which has an uncontestable effect on human health. Although bitter compounds are often associated with toxic substances a large number of nutritionally significant food sources contain bitter phytochemicals (e.g., broccoli [1], spinach [2]) many of which can have beneficial value [1, 3] Understanding how bitter taste is perceived and detected is of great importance to understanding diet selection [4] and increasing the acceptability of pediatric medicines [19]. Under normal feeding and drinking conditions taste compounds must inescapably mix with saliva before reaching their receptor targets but very little work has been done examining how salivary proteins modulate taste stimuli and alter bitter taste perception. Seventy percent of all salivary proteins make up a class of proteins referred to as proline-rich proteins (PRPs). PRP production is induced in rats by dietary exposure to tannic acid, a class of plant compounds that animals, including humans, regularly consume. It has been hypothesized that PRPs alter the acceptability of tannic acid by binding to tannins and thereby reduce the perceived intensity of the tannic acid solution [10, 11]. There is evidence to suggest that these proteins may have a similar relationship with other bitters. They are produced in close proximity to bitter taste receptors [13]. Genes for PRPs and bitter taste receptors are interspersed on the same chromosome [5] and lastly, gene linkage studies have implicated a role for PRPs bitter acceptance in humans and mice [15-18]. Specific Aim 1 will establish if long term exposure to bitter compounds can increase the expression of PRPs and establish whether oral exposure is necessary and sufficient to cause induction. Saliva will be analyzed for PRP content before and after exposure to diets adulterated with bitter compounds, including quinine and tannic acid. To isolate the site of exposure necessary for PRP induction rats will also be given tannic acid via either oral or gastric exposure. The ability or inability to induce PRP production is not sufficient to predict interactios between the proteins and the bitter tastants. Therefore, Specific Aim 2 will establish if PRP induction can alter the detection threshold for and superthreshold responsiveness to multiple bitter stimuli. Rats will be used to derive psychophysical detection curves of several bitter tastants in the presence and absence of PRPs. Likewise, responsiveness in the suprathreshold range will be assessed in the presence and absence of PRPs with a series of brief-access tests. Collectively, these experiments will test the hypothesis that PRPs alter taste sensitivity for bittr taste stimuli and ultimately blunt unconditioned taste avoidance responses to these compounds. Together these aims could inform methods for increasing the palatability of healthy phytochemicals and pediatric medicines. PUBLIC HEALTH RELEVANCE: Understanding how bitter taste is perceived and detected is of great importance to understanding diet selection, which has an overwhelming effect on human health. A large number of nutritionally significant food sources contain bitter phytochemicals many of which can have beneficial value and many pediatric medicines are rejected due to the bitter side taste. Understanding variation in taste perception may assist in efforts to promote healthy eating in children and adults.

描述（由申请人提供）：苦味感知的变化可能在饮食选择中起关键作用，这对人类健康具有不可忽视的影响。虽然苦味化合物通常与有毒物质有关，但大量营养重要的食物来源含有苦味植物化学物质（例如，西兰花[1]，菠菜[2]），其中许多都具有有益的价值[1，3]了解苦味是如何感知和检测的，对于理解饮食选择[4]和提高儿科药物的可接受性[19]非常重要。在正常的进食和饮水条件下，味觉化合物在到达它们的受体靶点之前必须不可避免地与唾液混合，但是很少有人研究唾液蛋白如何调节味觉刺激和改变苦味感知。所有唾液蛋白的70%组成一类被称为富含脯氨酸蛋白（PRPs）的蛋白质。PRP的产生是通过饮食暴露于单宁酸诱导的，单宁酸是动物（包括人类）经常食用的一类植物化合物。据推测，PRP通过与单宁结合而改变单宁酸的可接受性，从而降低单宁酸溶液的感知强度[10，11]。有证据表明，这些蛋白质可能与其他苦味有类似的关系。它们是在接近苦味受体的地方产生的[13]。PRP和苦味受体的基因散布在同一染色体上[5]，最后，基因连锁研究表明PRP在人类和小鼠中的苦味接受作用[15-18]。 具体目标1将确定长期暴露于苦味化合物是否会增加PRP的表达，并确定口服暴露是否是必要的且足以引起诱导。在暴露于掺入苦味化合物（包括奎宁和鞣酸）的饮食前后，将分析唾液中PRP的含量。为了隔离PRP诱导所需的暴露部位，还将通过经口或胃暴露给予大鼠单宁酸。诱导PRP产生的能力或不诱导PRP产生的能力不足以预测蛋白质和促苦味剂之间的相互作用。因此，具体目标2将确定PRP诱导是否可以改变对多种苦味刺激的检测阈值和超阈值反应性。在存在和不存在PRP的情况下，将使用大鼠推导出几种苦味剂的心理物理检测曲线。同样，在存在和不存在PRP的情况下，将通过一系列可重复使用试验评估阈上范围内的反应性。总的来说，这些实验将测试PRP改变对苦味刺激的味觉敏感性并最终钝化对这些化合物的无条件味觉回避反应的假设。这些目标可以为提高健康植物化学物质和儿科药物的适口性提供信息。 公共卫生相关性：了解苦味是如何被感知和检测的，对于理解对人类健康有着压倒性影响的饮食选择非常重要。大量营养重要的食物来源含有苦味植物化学物质，其中许多具有有益的价值，许多儿科药物由于苦味而被拒绝。了解味觉的变化可能有助于促进儿童和成人的健康饮食。