Healthy
Conditions
Keywords
ENaC, Exosomes, Urinary biomarker, Salt regulation
Brief summary
The hypothesis is that changes in the epithelial sodium channel (ENaC) in the kidney is reflected in urinary exosomes and that the amount of ENaC as well as the cleavage degree is upregulated in conditions with low salt.
Detailed description
Methods: Exosomes will be isolated from spot urine by ultracentrifugation and tested using western blotting. In-house developed antibodies against different parts of the ENaC gamma subunit as well as commercial antibodies will be used. A marker for exosomes will validate the presence of exosomes in the urine. Power considerations: In this cross over salt-intervention study with quantification of ENaC the investigators refer to a published study regarding the sodium-chloride co-transporter (NCC) in the kidney, were rats where given aldosterone infusion or a low salt diet. In this study n=6 was sufficient to detect a 2-3 fold change in NCC in urinary exosomes. Furthermore 5 patients with primary aldosteronism had a significant increase in NCC in urinary exosomes (N. Lubbe et al, Hypertension 2012). On the basis of this the investigators choose to test 10 persons, but are not able to make a regular power calculation.
Interventions
DIETARY_SUPPLEMENTHigh salt diet followed by low salt diet
High salt diet (250 mmol/day) in 5 days followed by low salt diet (60-70 mmol/day) in 5 days.
DIETARY_SUPPLEMENTLow salt diet followed by high salt diet
Low salt diet (60-70 mmol/day) in 5 days followed by high salt diet (250 mmol/day) in 5 days.
Sponsors
Danish Diabetes Academy
Odense University Hospital
Beckett Foundation
University of Southern Denmark
Study design
Allocation
NON_RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
NONE
Masking description
open label
Eligibility
Sex/Gender
MALE
Age
20 Years to 40 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy men aged 20-40 * Body Mass Index (BMI, weight/height\^2) between 18 and 25.
Exclusion criteria
* Increased blood pressure (hypertension) or in treatment for high blood pressure * Diabetes * Regular medical intake * Smoking * Expectation of lacking cooperation or lack of understanding of the experiment * Clinical relevant organic or systemic disease including malign disease * Decreased kidney function
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Changes in epithelial sodium channel (ENaC) appearance in urinary exosomes | After 5 days on high or low salt diet | Semiquantitative western blotting |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Plasma aldosterone | Before study start and after 5 days on high or low salt diet | Concentration in plasma. |
| Renin | Before study start and after 5 days on high or low salt diet | Concentration in plasma. |
Countries
Denmark
Outcome results
None listed