The Molecular Basis for a Broad Range of Phenotypes Related to hTAS2R38
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 70
- 试验地点
- 1
- 主要终点
- Bitter taste thresholds
研究概览
简要总结
This single-site, within-subject, experimental study is designed to test the hypothesis that individuals express taste receptors differently and have different sensitivities to bitter taste samples, which results from uneven expression. Subjects will include 100 racially and ethnically diverse, healthy adults. All subjects will provide saliva samples for genetic analysis and undergo taste testing with common psychophysical stimuli. From the pool of 100 subjects, 36 subjects from the common heterozygous group (PAV/AVI) and two from each homozygous group (AVI/AVI, nontaster and PAV/PAV, taster) will be invited to return for two additional sessions. During both sessions the investigators will 1) measure bitterness thresholds for PROP, a common psychophysical stimulus; 2) measure bitterness perception of several vegetables; 3) obtain a saliva sample and 4) collect taste papillae. The investigators will then isolate DNA and RNA from the taste papillae and isolate DNA from saliva to evaluate molecular differences over time and between individuals and how it relates to taste psychophysics. All psychophysical and cellular measurements will be done during both sessions so that the investigators can determine how much variation is observed over a one-week time period in both cellular phenotype and psychophysical phenotype.
研究设计
- 研究类型
- Observational
- 观察模型
- Case Only
- 时间视角
- Cross Sectional
入排标准
- 年龄范围
- 18 Years 至 40 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Key inclusion criteria include age 18-40 years; English speaking, and good health at the time of study participation.
排除标准
- •Key exclusion criteria include cigarette smoking, which alters taste perception, oral disease and subjects undergoing Coumadin therapy. Subjects showing signs of oral disease, including tongue lesions or xerostomia will be excluded from tongue biopsy and therefore excluded from the study. Subjects undergoing Coumadin therapy will be excluded from tongue biopsy due to the risk of bleeding, and therefore excluded from the study. Subjects will not be excluded because of economic status, gender, race or ethnicity.
结局指标
主要结局
Bitter taste thresholds
时间窗: 2 days of testing (2 hours each)
Thresholds for propylthiouracil (PROP) will be measured using modified Harris-Kalmus recognition thresholds.
Taste intensity and hedonic ratings of vegetables
时间窗: 3 days of testing (1-2 hours each)
Subjects will rate the intensity of five basic taste qualities (bitter, salt, sweet, sour, umami) and the liking of PROP, urea, quinine, caffeine, denatonium solutions and pureed vegetables using the general labelled magnitude scale (gLMS)
TAS2R Genotype
时间窗: 1 day of testing (1-1.5 hours)
Genotype of several TAS2Rs will be determined from DNA extracted from a saliva sample.
mRNA expression levels
时间窗: 2 days of testing (2 hours each)
Expression of taste and related genes will be determined from mRNA extracted from human taste tissue obtained via tongue biopsy.
次要结局
- biometrics(1 day (1-1.5 hours))
- Dietary habits(2 days (2 hours each))
研究者
Julie A. Mennella
Member
Monell Chemical Senses Center