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Modulation of plasma aldosterone by physiological changes in hydrogen ion concentration
G V Jones1, B M Wall, H H Williams
1Department of Medicine, Veterans Affairs Medical Center, Memphis, Tennessee.
The American Journal of Physiology
|February 1, 1992
Summary
Extracellular hydrogen ion concentration (pH+) weakly influences basal aldosterone secretion. This effect is not apparent when other stimuli, like ACTH, are present.
Area of Science:
- Nephrology
- Endocrinology
- Physiology
Background:
- Aldosterone secretion is regulated by multiple factors.
- The role of extracellular hydrogen ion concentration (pH+) in aldosterone regulation requires further clarification.
Purpose of the Study:
- To investigate the effect of extracellular hydrogen ion concentration (pH+) on aldosterone secretion.
- To determine if pH+ influences ACTH-stimulated aldosterone and cortisol secretion.
Main Methods:
- Studies were conducted on hemodialysis patients with controlled plasma potassium and body weight.
- Dialysate bicarbonate concentrations were altered to manipulate extracellular pH+.
- ACTH-stimulated secretion was assessed in a separate cohort after dexamethasone pretreatment.
Main Results:
- Changes in extracellular pH+ correlated with changes in plasma aldosterone concentration (Pa) in basal conditions (r = 0.659, P < 0.001).
- No correlation was found between Pa and plasma potassium, sodium, ACTH, or plasma renin activity (PRA).
- Extracellular pH+ did not affect Pa or plasma cortisol concentration during ACTH stimulation.
Conclusions:
- Physiological changes in extracellular pH+ have a weak modulating effect on basal aldosterone secretion.
- This effect of pH+ on aldosterone is not evident in the presence of acute stimuli such as ACTH.