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Gustin Gene Polymorphism and 6-n-propylthiouracil (PROP) Taste (gustinprop)

This study has been completed.
Sponsor:
ClinicalTrials.gov Identifier:
NCT01097915
First Posted: April 2, 2010
Last Update Posted: May 30, 2017
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Information provided by (Responsible Party):
Iole Tomassini Barbarossa, University of Cagliari
  Purpose
The investigators evaluate the possible association of PROP taste with gustin gene polymorphism rs2274333 (A/G), salivary zinc ion concentration and BMI. In addition, it has also been evaluated PROP taste sensitivity by recording monophasic potentials from the tongue.

Condition
Dysgeusia

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: Sensitivity to 6-n-propylthiouracil (PROP) Association With Gustin (CA6) Gene Polymorphism, Salivary Zinc and BMI in Humans

Resource links provided by NLM:


Further study details as provided by Iole Tomassini Barbarossa, University of Cagliari:

Primary Outcome Measures:
  • Association Between Gustin Gene Polymorphism and PROP Sensitivity [ Time Frame: 7 months ]

    We examine associations between PROP status and the polymorphism rs2274333 (A/G) of the gene that codify for the salivary protein, gustin/CA6, Which has been suggested as a trophic factor that promotes growth and development of taste buds by acting on taste bud stem cells.

    The intensity of taste perception evoked by PROP and NaCl solutions was estimated to evaluate PROP taster status and molecular analysis of the gustin gene polymorphism was performed in individuals classified by PROP status using PCR techniques.



Secondary Outcome Measures:
  • Association Between PROP Sensitivity and Saliva Zinc Ion Concentration [ Time Frame: 7 months ]
    Since the enzymatic function of gustin (CA6) depends upon the presence of Zn at its active site we measured the salivary zinc ion concentration in subjects classified as super-taster, medium taster and non-taster.The salivary Zn2+ concentration was measured with a QuantiChromTM zinc Assay kit (Gentaur, Brussels, Belgium) where the color intensity is directly proportional to the Zn2+ concentration in the sample.

  • Electrophysiological Recordings From the Tongue for the Objective Evaluation of Individual Variations of 6-n-propylthiouracil (PROP) Sensitivity [ Time Frame: 1 year ]
    electrophysiological recordings from the tongue of 43 subjects classified for their taste sensitivity to 6-n- propyltiouracil (PROP) and genotyped for the specific receptor gene, TAS2R38. Density of fungiform papillae was also determined in each subject. The biopotentials were recorded by means of differential electrophysiological derivations between two silver electrodes, one in contact with the ventral surface of the tongue and one in perfect adhesion with the dorsal surface.

  • Association Between PROP Sensitivity and BMI [ Time Frame: 7 months ]
    Since individual ability to taste PROP may be correlated with BMI, we determined BMI (kg/m^2) in subjects classified as super-taster, medium taster and non-taster.Weight (kg) and height (m) were recorded for each subject.

  • Taste Perception of Sweet, Sour, Salty, Bitter and Umami and Changes Due to L-Arginine Supplementation, as a Functin of Genetic Ability to Taste PROP. [ Time Frame: 8 months ]
    Taste perception was assessed by testing the ability to recognize, and the responsiveness to, representative solutions of the five taste qualities, also when supplemented with L-Arg, in subjects classified as PROP-tasters.


Biospecimen Retention:   Samples With DNA
DNA and zinc analyses in saliva

Enrollment: 170
Study Start Date: October 2009
Study Completion Date: June 2016
Primary Completion Date: December 2009 (Final data collection date for primary outcome measure)
Groups/Cohorts
PROP taste sensitivity
PROP Sensitive and non sensitive individuals are defined as "Tasters" and "Non-tasters", respectively. Taster are further divided in "Super-taster" who perceived PROP as extremely bitter and "Medium tasters" who perceived PROP as moderately bitter.

Detailed Description:

The investigators evaluate the possible association of PROP taste with gustin gene polymorphism rs2274333 (A/G), salivary zinc ion concentration and BMI.

Furthermore, we apply direct measures of the gustatory system activation following stimulation with PROP, obtained by electrophysiological recordings from the tongue of subjects classified for taster status, genotyped for the specific receptor gene (TAS2R38), and in which papilla density was determined.

  Eligibility

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Ages Eligible for Study:   20 Years to 30 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Probability Sample
Study Population
Seventy-five non-smoking volunteers (28 men and 47 women) were recruited for the study. Participants between 20-30 years were eligible for the study. Thresholds for the 4 basic tastes were evaluated in all subjects in order to rule out any gustatory impairment. The volunteers showed no variation of body weight > 5 kg over the last 3 mo. They were not following a prescribed diet or using medications that might interfere with taste perception; none had food allergies. They were assessed for cognitive eating behaviours using the Three-Factor Eating Questionnaire
Criteria

Inclusion Criteria:

  • no variation of body weight > 5 kg over the last 3 mo BMI within 20-25 Age between 20-30

Exclusion Criteria:

  • gustatory impairment following a prescribed diet or using medications that might interfere with taste perception food allergies smokers
  Contacts and Locations
Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01097915


Locations
Italy
Sezione di Farmacologia Clinica del Dipartimento di Neuroscienze, San Giovanni di Dio Azienda Ospedaliero Universitaria di Cagliari
Cagliari, Ca, Italy, 09124
Sponsors and Collaborators
University of Cagliari
Investigators
Principal Investigator: Iole Tomassini Barbarossa, PhD Dipartimento di Biologia Sperimentale Sezione di Fisiologia Generale Università di Cagliari
  More Information

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Iole Tomassini Barbarossa, Associate Professor, University of Cagliari
ClinicalTrials.gov Identifier: NCT01097915     History of Changes
Other Study ID Numbers: UNICADBSITB-1
First Submitted: April 1, 2010
First Posted: April 2, 2010
Results First Submitted: July 19, 2016
Results First Posted: December 21, 2016
Last Update Posted: May 30, 2017
Last Verified: May 2017
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Undecided
Plan Description: Data of this study are available from the principal investigator of this study upon request

Keywords provided by Iole Tomassini Barbarossa, University of Cagliari:
PROP taste sensitivity
Gustin (CAVI) polymorphism
Salivary zinc
BMI
Electrophysiological recording from the tongue

Additional relevant MeSH terms:
Dysgeusia
Taste Disorders
Sensation Disorders
Neurologic Manifestations
Nervous System Diseases
Signs and Symptoms
Propylthiouracil
Antimetabolites
Molecular Mechanisms of Pharmacological Action
Antithyroid Agents
Hormone Antagonists
Hormones, Hormone Substitutes, and Hormone Antagonists
Physiological Effects of Drugs