Increased 18-hydroxycorticosterone responses to frusemide in essential hypertension

Area of Science:

• Endocrinology
• Nephrology
• Cardiovascular Physiology

Background:

• Benign essential hypertension is a complex condition often involving the renin-angiotensin-aldosterone system.
• Diuretics like frusemide can influence hormonal responses related to blood pressure regulation.

Purpose of the Study:

• To investigate the plasma hormonal responses to intravenous frusemide in patients with benign essential hypertension compared to normotensive controls.
• To explore the relationship between angiotensin II, aldosterone, and 18-hydroxycorticosterone levels following diuretic administration in hypertensive individuals.

Main Methods:

• Plasma concentrations of angiotensin II (AII), aldosterone, 18-hydroxycorticosterone, and cortisol were measured.
• Measurements were taken in seven hypertensive patients and seven age-matched controls before and for 2 hours after a 40 mg intravenous frusemide injection.
• Integrated hormonal responses to frusemide were calculated.

Main Results:

• Frusemide administration led to significant increases in AII, aldosterone, and 18-hydroxycorticosterone in normal subjects within 15 minutes.
• Aldosterone and AII responses were closely related in normal subjects.
• Hypertensive patients exhibited significantly greater integrated 18-hydroxycorticosterone responses compared to controls (median 970 vs. 180 nmol.h-(1).1-(1), P<0.05).
• Three hypertensive patients showed normal aldosterone responses despite subnormal AII increases.

Conclusions:

• Some patients with hypertension display an enhanced adrenal corticosteroid response to frusemide.
• This enhanced response likely indicates increased sensitivity to angiotensin II in hypertensive individuals.
• The findings suggest a potential role for altered sensitivity to angiotensin II in the pathophysiology of benign essential hypertension.