NCT02084797

V2 Receptor Effects on Fluid Regulation and Performance

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

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 10 (actual)
• Sponsor: Oakland University · Academic / Other
• Sex: All
• Age: 18 Years – 60 Years
• Healthy volunteers: Accepted

Summary

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.

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.

Conditions

• Electrolyte Imbalance
• Hyponatremia
• Hypernatremia

Interventions

Type	Name	Description
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).

Timeline

• Start date: 2011-06-01
• Primary completion: 2011-10-01
• Completion: 2012-10-01
• First posted: 2014-03-12
• Last updated: 2016-05-12
• Results posted: 2016-05-12

Locations

1 site across 1 country: United States