Acute and long-term effects of ACE inhibition on renal haemodynamics in glomerular and interstitial nephropathies.
BACKGROUND
Angiotensin-converting enzyme (ACE) inhibitors are the drugs of choice for the treatment of hypertension in patients with non-diabetic nephropathies. However, not every trial has reported better results with ACE inhibitors (ACE-I) than with other drugs. This study investigates whether the acute and chronic effects of ACE inhibition on renal and glomerular haemodynamics are similar in glomerular and interstitial nephropathies.


METHODS
We studied 20 hypertensive patients, on their usual diet, with mild-to-moderate chronic renal failure secondary to non-diabetic nephropathy. After a three-week wash out period, we determined plasma clearances of para-amino-hippurate and inulin before, and after acute oral administration of either enalapril or ramipril. This same test was carried out after one and two years of treatment with the same drug.


RESULTS
Acute ACE inhibition causes a decrease of renal perfusion, glomerular filtration and pressure with an increase of afferent resistances. Long-term ACE inhibition is associated only with a decrease in renal perfusion, with a non-significant tendency to higher filtration fraction and lower afferent resistances. All the renal haemodynamic modifications mentioned above are present only in patients with glomerular diseases.


CONCLUSIONS
Renal and glomerular haemodynamic responses are not similar after acute and chronic ACE inhibition. Only patients with glomerular diseases show acute or long-term responses to ACE inhibition.
Guidi
Ettore
E
Centro di Ricerca Clinica in Nefrologia e Ipertensione Arteriosa, Unità Operativa di Nefrologia, Dialsi e Terapia del Trapianto Renale, Ospedale Niguarda, Milano, Italy. etguid@tin.it
Minetti
Enrico E
EE
Cozzi
Maria Grazia
MG
D000328:Adult; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D004656:Enalapril / Q000627:therapeutic use; D005260:Female; D005919:Glomerular Filtration Rate; D005921:Glomerulonephritis / Q000188:drug therapy* / Q000503:physiopathology*; D006801:Humans; D006977:Hypertension, Renal / Q000188:drug therapy* / Q000503:physiopathology*; D007444:Inulin; D007676:Kidney Failure, Chronic / Q000503:physiopathology; D007677:Kidney Function Tests; D007678:Kidney Glomerulus / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009395:Nephritis, Interstitial / Q000188:drug therapy* / Q000503:physiopathology*; D017257:Ramipril / Q000627:therapeutic use; D012079:Renal Circulation / Q000187:drug effects*; D010130:p-Aminohippuric Acid / Q000097:blood
D000806:Angiotensin-Converting Enzyme Inhibitors; D004656:Enalapril; D007444:Inulin; D017257:Ramipril; D010130:p-Aminohippuric Acid