V2 Receptor Effects on Fluid Regulation and Performance

April 6, 2016 updated by: Tamara Hew-Butler, Oakland University

Revisiting the Human Sweat Gland - Does Arginine Vasopressin Modulate Sweat Sodium Concentration Via the V2 Receptor?

This primary aim of this study was to critically assess whether or not sweat water content and sodium concentration were acutely regulated by dynamic changes in antidiuretic hormone (arginine vasopressin or AVP) acting on the Vasopressin 2 receptor (V2R) during exercise. Secondary aims were to evaluate running performance and core temperature to further characterize the role of AVP in the coordinated balance of fluid and temperature homeostasis during exercise. The primary hypothesis was that activation of the V2R in sweat glands would result in water reabsorption and fluid conservation during endurance exercise.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Ten healthy habitual runners (> 50km running per week) between 18-60 years of age participated in this double blind randomized control trial. Each subject presented to the exercise lab on four separate occasions. Trial 1 was a familiarization trial to determine each subject's maximal aerobic capacity and peak treadmill running speak (VO2 Peak test). Trials 2, 3 and 4 utilized the same exact protocol, differing only in pharmacological intervention. In a randomized, double-blind order (both participant and investigator blinded to the intervention), either a placebo pill, the V2 receptor antagonist tolvaptan (Samsca™, 30mg tablet), or the V2 receptor agonist desmopressin (DDAVP™, 0.2mg tablet) was ingested along with the CorTemp™ Core Temperature Sensor two hours before commencement of the Exercise Trial with 240mL of bottled water. The exercise protocol consisted of 60 minutes of treadmill running at 60% of peak speed (steady-state) followed by a performance test (the VO2 Peak test). Blood, saliva and urine, were collected before the exercise trial (baseline) and again after both the steady-state run and performance runs. Sweat was obtained from sweat patches after both the steady-state and performance runs. Core temperature, fluid intake, performance time, body weight, thirst and sodium palatability ratings were also assessed. Free access to water was allowed during the trial and all urine produced during the trial was measured and collected. The main outcome measure was sweat sodium concentration.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
10

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Michigan
      • Rochester, Michigan, United States, 48309
        • Oakland University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 60 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Healthy (no acute or chronic medical conditions or regular prescription medication use), habitual (>50km/week)
  • Distance runners between the ages of 18-60 years.

Exclusion Criteria:

  • Individuals with chronic medical problems which require regular prescription medication
  • Runners with pre-existing kidney problems
  • Unable to sense thirst
  • Difficulty swallowing
  • Gastrointestinal disorders
  • History of fainting associated with blood draw.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: all study participants
All study participants received all interventions. V2R Antagonist: 30mg Tolvaptan tablet ingested 2 hours before exercise. V2R agonist: 0.2mg DDAVP tablet ingested 2 hours before exercise Placebo
Drug: V2R (Vasopressin 2 receptor)
All ten subjects were used as their own controls in this double-blind, randomized controlled trial assessing the effect of the V2R on sweat sodium concentration via use of a V2R blocker (antagonist), stimulator (agonist), against a placebo (drug naive state).
Other Names:
  • V2R antagonist: tolvaptan (30mg tablet)
  • V2R agonist: desmopressin (0.2mg tablet)

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Sweat Sodium Concentration Obtained After the Steady-state Portion of the Trial
Time Frame: 4 study trials (4 weeks)
Changes in sweat sodium concentration will parallel changes in urine sodium concentration with use of the V2R antagonist, agonist and placebo if the primary hypothesis is true (sweat sodium is regulated by the V2R, similar to how urine sodium is regulated by principle cells located within in the kidney collecting duct)
4 study trials (4 weeks)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Urine Sodium Concentration After the Steady-state Portion of the Trial
Time Frame: 4 study trials (4 weeks)
Changes in urine sodium concentration after use of the V2R antagonist, agonist and placebo interventions will verify whether or not pharmacologic activation or inhibition was successfully induced.
4 study trials (4 weeks)
Blood Sodium Concentration
Time Frame: 4 study trials (4 weeks)
Measurement of blood sodium concentration will determine if normonatremia (blood sodium concentrations within the normal physiological range of 135-145mmol/L) were maintained throughout the trial with appropriate fluid intake during the V2R antagonist, agonist and placebo intervention trials.
4 study trials (4 weeks)
Saliva Sodium Concentration
Time Frame: 4 trials (4 weeks)
Measurement of salivary sodium concentration will allow us to determine if the V2R antagonist, agonist and placebo interventions activate aquaporin-5 (AQP5) water channels that are also located in sweat glands. If the V2R acts on the sweat glands through AQP5, there should be parallel changes in sweat, urine and saliva sodium concentrations with each pharmaceutical intervention.
4 trials (4 weeks)

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Body Weight
Time Frame: 4 trials (4 weeks)
Changes in body weight during the V2R antagonist, agonist and placebo conditions will provide researchers with an additional measure of overall fluid balance (fluid in versus fluid out) as well as an estimate of overall sweat water losses.
4 trials (4 weeks)
Core Temperature
Time Frame: 4 trials (4 weeks)
Measurement of core temperature using an ingestible CorTemp sensor during the V2R antagonist, agonist and placebo trials will allow researchers to assess if fluid homeostasis and thermoregulation were intertwined in response to each pharmacological intervention.
4 trials (4 weeks)
Thirst Rating
Time Frame: 4 trials (4 weeks)
To determine if fluid intake behaviors were appropriately regulated in response to the V2R antagonist, agonist and placebo conditions during exercise.
4 trials (4 weeks)
Sodium Palatability Ratings
Time Frame: 4 weeks (4 trials)
To determine if sodium preference ratings were appropriately regulated in response to the V2R antagonist, agonist and placebo conditions during exercise.
4 weeks (4 trials)
Performance
Time Frame: 4 trials (4 weeks)
To determine if exercise performance, as determined by overall exercise time, was affected in response to the V2R antagonist, agonist and placebo conditions.
4 trials (4 weeks)
Fluid Intake
Time Frame: 4 weeks (4 trials)
To determine if fluid intake behaviors were appropriately regulated in response to the V2R antagonist, agonist and placebo conditions during exercise.
4 weeks (4 trials)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Oakland University

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Georgetown University

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Tamara D Hew-Butler, PhD, Oakland University
  • Study Director: Joseph G Verbalis, MD, Georgetown University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
June 1, 2011

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
October 1, 2011

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
October 1, 2012

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 10, 2014

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 11, 2014

First Posted (Estimate)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 12, 2014

Study Record Updates

Last Update Posted (Estimate)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 12, 2016

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 6, 2016

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2016

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • RAM#4713

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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