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ENaC processing in rat kidney: effects of salt loading and ADH
Gustavo Frindt1, Theresa Rohan1, Ryan Schreiner2
1Department of Biochemistry and Biophysics, Weill-Cornell Medicine, New York, New York, United States.
American Journal of Physiology. Renal Physiology
|April 17, 2026
Summary
Dietary sodium loading and anti-diuretic hormone (ADH) impact epithelial sodium channel (ENaC) processing. ADH stimulates ENaC subunit synthesis, while sodium loading inhibits protein trafficking, independent of aldosterone.
Area of Science:
- Nephrology
- Molecular Biology
- Endocrinology
Background:
- The epithelial sodium channel (ENaC) is crucial for sodium homeostasis and blood pressure regulation.
- ENaC activity is tightly controlled by various hormones and physiological conditions, including sodium balance and anti-diuretic hormone (ADH).
- Understanding ENaC processing is key to comprehending renal sodium handling.
Purpose of the Study:
- To investigate the acute effects of dietary sodium loading and ADH on ENaC processing.
- To elucidate the mechanisms controlling ENaC subunit maturation and trafficking.
- To differentiate the roles of aldosterone and ADH in regulating ENaC.
Main Methods:
- Rats were subjected to acute dietary sodium repletion or administration of dDAVP (a V2-type ADH receptor agonist).
- ENaC subunit abundance, including cleaved and mature forms, was assessed using Western blotting.
- mRNA levels for ENaC subunits were measured to evaluate transcriptional regulation.
Main Results:
- Acute salt repletion decreased the abundance of fully processed ENaC proteins (cleaved α/γENaC, mature βENaC) within 2.5 hours, independent of aldosterone.
- dDAVP administration increased cleaved γENaC and αENaC, as well as full-length γENaC, within 2 hours.
- Neither sodium loading nor dDAVP significantly altered ENaC subunit mRNA levels.
Conclusions:
- ENaC subunit processing is acutely modulated by aldosterone-independent mechanisms.
- Dietary sodium loading inhibits the forward trafficking of assembled ENaC proteins.
- ADH stimulates ENaC subunit synthesis, contributing to ENaC regulation.
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