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Atrial natriuretic factor in human autonomic failure
H Kaufmann1, E Oribe, A R Pierotti
1Department of Neurology, Mount Sinai School of Medicine, City University of New York, New York 10029.
Neurology
|July 1, 1990
Summary
Patients with autonomic failure do not have excessive atrial natriuretic factor (ANF) levels. This study found lower ANF concentrations and appropriate ANF regulation, ruling out high ANF as a cause of their symptoms.
Area of Science:
- Cardiovascular Physiology
- Endocrinology
- Nephrology
Background:
- Autonomic failure can cause orthostatic hypotension and nocturnal polyuria.
- Atrial natriuretic factor (ANF) plays a role in regulating fluid and electrolyte balance.
- The role of ANF in the pathophysiology of autonomic failure is not fully understood.
Purpose of the Study:
- To investigate if elevated circulating atrial natriuretic factor (ANF) levels cause orthostatic hypotension and nocturnal polyuria in patients with autonomic failure.
- To determine the circadian variation and postural response of plasma ANF in these patients.
Main Methods:
- Measured plasma ANF concentrations and urinary sodium excretion over 24 hours in patients with autonomic failure and healthy controls.
- Assessed ANF response to head-up tilt and mineralocorticoid administration to evaluate extracellular fluid volume regulation.
Main Results:
- Patients with autonomic failure had significantly lower plasma ANF concentrations compared to controls.
- Nocturnal urinary sodium excretion was higher than daytime excretion in patients, with a concurrent decrease in plasma ANF.
- Plasma ANF levels responded appropriately to changes in posture and extracellular fluid volume.
Conclusions:
- Excessive circulating atrial natriuretic factor (ANF) is not responsible for orthostatic hypotension or nocturnal polyuria in patients with autonomic failure.
- Appropriate regulation of ANF occurs in patients with autonomic failure, despite their symptoms.