Basal and saline-stimulated plasma atrial natriuretic hormone in Cushing's syndrome.
The pathogenesis of hypertension associated with Cushing's syndrome is incompletely understood. We have studied basal and saline-stimulated levels of plasma atrial natriuretic hormone in 10 subjects with active Cushing's syndrome (8 F: 2 M), aged 43 +/- 4 years (mean +/- SEM). Ten age- and sex-matched normal control subjects were also studied. Subjects fasted from 22.00 h, rose at 07.45 h, and remained ambulant until 09.45 h when blood was taken for plasma ANH, plasma renin activity and serum aldosterone. Subjects then rested supine until 10.00 h when blood was again taken, and blood pressure recorded. Then, while subjects remained supine, 21 of 0.9% NaCl were infused between 10.00 and 14.00 h. Blood was taken hourly. Basal plasma ANH was 8.0 +/- 0.9 pmol/l in Cushing's subjects and 6.9 +/- 2.5 pmol/l in controls. Levels increased in response to saline in both groups, and became significantly higher in the group of patients with Cushing's syndrome (14.00 h level 21.3 +/- 3.9 vs 10.4 +/- 1.9 pmol/l; p less than 0.05). Serum aldosterone and plasma renin activity were not different between groups. Mean blood pressure was higher in patients (114 +/- 4 vs 91 +/- 7 mmHg; p less than 0.05). Urinary sodium excretion was not different between groups before saline, but during the four hours of saline was higher in Cushing's subjects (133 +/- 12 vs 67 +/- 11 mmols; N = 6; p less than 0.05). Our results suggest that during salt loading the exaggerated natriuresis seen in the Cushing's group may have been caused by ANH.
McKnight
J A
JA
Sir George E. Clark Metabolic Unit, Royal Victoria Hospital, Belfast, Northern Ireland.
McCance
D R
DR
Roberts
G
G
Sheridan
B
B
Atkinson
A B
AB
D000328:Adult; D000450:Aldosterone / Q000097:blood; D009320:Atrial Natriuretic Factor / Q000097:blood* / Q000502:physiology; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D003480:Cushing Syndrome / Q000097:blood* / Q000503:physiopathology / Q000652:urine; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012083:Renin / Q000097:blood; D012964:Sodium / Q000652:urine; D012965:Sodium Chloride / Q000494:pharmacology*
D012965:Sodium Chloride; D000450:Aldosterone; D009320:Atrial Natriuretic Factor; D012964:Sodium; D012083:Renin