The Influence of High and Low Salt on Exosomes in the Urine
Study Details
Study Description
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.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
N/A |
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.
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Experimental: Healthy male test subjects 1-5 High salt diet followed by low salt diet |
Dietary Supplement: High 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.
|
| Experimental: Healthy male test subjects 6-10 Low salt diet followed by high salt diet |
Dietary Supplement: Low 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.
|
Outcome Measures
Primary Outcome Measures
- Changes in epithelial sodium channel (ENaC) appearance in urinary exosomes [After 5 days on high or low salt diet]
Semiquantitative western blotting
Secondary Outcome Measures
- 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.
Eligibility Criteria
Criteria
Inclusion Criteria:
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Healthy men aged 20-40
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Body Mass Index (BMI, weight/height^2) between 18 and 25.
Exclusion Criteria:
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Increased blood pressure (hypertension) or in treatment for high blood pressure
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Diabetes
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Regular medical intake
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Smoking
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Expectation of lacking cooperation or lack of understanding of the experiment
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Clinical relevant organic or systemic disease including malign disease
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Decreased kidney function
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | University of Southern Denmark | Odense | Denmark | 5000 |
Sponsors and Collaborators
- University of Southern Denmark
- Danish Diabetes Academy
- Odense University Hospital
- Beckett Foundation
Investigators
- Study Director: Boye L Jensen, dr.med., phd, Cardiovascular and Renal Research, Institute of Moleculare Medicine, University of Southern Denmark
Study Documents (Full-Text)
None provided.More Information
Publications
- van der Lubbe N, Jansen PM, Salih M, Fenton RA, van den Meiracker AH, Danser AH, Zietse R, Hoorn EJ. The phosphorylated sodium chloride cotransporter in urinary exosomes is superior to prostasin as a marker for aldosteronism. Hypertension. 2012 Sep;60(3):741-8. doi: 10.1161/HYPERTENSIONAHA.112.198135. Epub 2012 Jul 30.
- Zachar RM, Skjødt K, Marcussen N, Walter S, Toft A, Nielsen MR, Jensen BL, Svenningsen P. The epithelial sodium channel γ-subunit is processed proteolytically in human kidney. J Am Soc Nephrol. 2015 Jan;26(1):95-106. doi: 10.1681/ASN.2013111173. Epub 2014 Jul 24.
- RZL-SDU-IMM-CVR