Hormonal responses to acute volume changes in anephric subjects

Area of Science:

• Endocrinology
• Renal Physiology

Background:

• The renin-angiotensin system is a key regulator of aldosterone secretion.
• The role of volume status in hormone regulation requires further investigation, especially in patients with kidney disease.

Purpose of the Study:

• To investigate the regulation of plasma aldosterone and cortisol concentrations in response to acute volume depletion.
• To determine the persistence of aldosterone responsiveness to ACTH after removal of the renin-angiotensin system.

Main Methods:

• Studied 18 chronically anephric and 4 recently nephrectomized subjects undergoing hemodialysis.
• Monitored plasma aldosterone, cortisol, ACTH, potassium, and blood pressure during volume-depleting and non-volume-depleting hemodialysis.

Main Results:

• Chronically anephric subjects showed no significant change in aldosterone but increased cortisol and ACTH during volume depletion.
• Recently nephrectomized subjects exhibited increased aldosterone, cortisol, and ACTH concordantly with volume depletion.
• Cortisol changes negatively correlated with diastolic blood pressure in anephric subjects.

Conclusions:

• Aldosterone regulation by volume is impaired in chronically anephric patients but present in recently nephrectomized ones.
• Aldosterone responsiveness to ACTH persists temporarily after renin-angiotensin system removal.
• Volume-related cortisol and ACTH changes occur independently of the renin-angiotensin system.