Captopril-induced hyperreninemia in cholesterol-fed rabbits.

Area of Science:

• Nephrology
• Cardiovascular Research
• Pharmacology

Background:

• Captopril is an angiotensin-converting enzyme inhibitor.
• Chronic hyperreninemia is a potential side effect of captopril.
• The effects of captopril-induced hyperreninemia on atherogenesis and kidney morphology are not fully understood.

Purpose of the Study:

• To investigate the effects of captopril-induced chronic hyperreninemia on atherogenesis.
• To describe and quantitate morphological changes in the juxtaglomerular apparatus of captopril-treated rabbits.

Main Methods:

• Four groups of normotensive New Zealand rabbits were used.
• Animals were fed either regular chow or a cholesterol-supplemented diet.
• Captopril was administered daily for six months.
• Plasma renin activity, blood urea nitrogen, arterial pressure, aldosterone, and hematocrit were measured.
• Morphometric analysis of the juxtaglomerular apparatus was performed.

Main Results:

• Captopril treatment significantly increased plasma renin activity and blood urea nitrogen.
• Systemic arterial pressure, plasma aldosterone, and hematocrit were reduced in captopril-treated groups.
• No significant effect on atherogenesis was observed.
• Significant hypertrophy and hyperplasia of the juxtaglomerular complex were found in all captopril-treated animals.

Conclusions:

• Captopril-induced hyperreninemia does not promote atherogenesis in this model.
• Captopril treatment leads to significant morphological and functional alterations in the kidney, specifically hypertrophy and hyperplasia of the juxtaglomerular apparatus.
• These renal changes are likely due to reduced blood pressure and impaired autoregulation of renal blood flow and glomerular filtration.