Reduction of albuminuria after angiotensin converting enzyme inhibition in various renal disorders.

The urinary albumin excretion measured by the albumin creatinine clearance ratio (Calb/Ccreat) and the mean supine arterial blood pressure (MAP) were studied before the start of ACE inhibition, at the start and during up to 1 year of ACE inhibition with Captopril or Enalapril in 35 patients with various chronic proteinuric renal disorders with or without renal failure, arterial hypertension and nephrotic syndrome. Before the start of ACE inhibition mean Calb/Ccreat, MAP, s-albumin and s-creatinine did not change. During ACE inhibition the Calb/Ccreat was reduced from 75% (p less than 0.05) in patients with minimal albuminuria to 41% (p less than 0.005) in patients with extensive albuminuria. Average reduction of albuminuria was 44% at one year's observation time. Serum albumin increased 9% (p less than 0.05), serum creatinine did not change significantly and MAP showed a slight, not uniformly significant decrease. The reduction of Calb/Ccreat was of the same order in the different renal disorders studied and was independent of the renal function, presence or absence of nephrotic syndrome and treatment with antihypertensive or immunosuppressive drugs. The decrease in Calb/Ccreat during ACE inhibition was related to the reduction in MAP at most time intervals, but Calb/Ccreat decreased also when MAP was unchanged or increased. Thus the decrease in Calb/Ccreat during ACE inhibition does not only seem to be a consequence of a decrease in the systemic arterial blood pressure but reasonably also due to changes in the intra-renal hemodynamics and most probably a decrease in the glomerular capillary pressure.