The purpose of this study was to define the renal effect of enalapril in patients with essential
hypertension with mild to
moderate renal dysfunction. 27 patients, aged 58±8 years,were divided into three groups:(1)azotemia stage(n=8):creatinine clearance rate (Ccr):10-50ml/min and/or serum creatinine(Scr):200-445μmol/L.(2)compensation stage(n=9):Ccr:50-80 ml/min and/or Scr 120-200 μmol/L.(3)normal renal function stage (n=10).The following parameters were measured:renal plasma flow (RPF)assesed by paraminohippurate clearance rate (HPLC method);glomerular filtration rate(GFR) assesed by sodium sulfosulfate clearance rate with microcolorimetry; urinary microprotein excretion,including albumin(UMAE/Cr),transferin (UMTE/Cr), IgG(UMGE/Cr),retinol binding protein(RBP)and N-acetyl-β-D-glucosaminide,(NAG)by ELISA method,before and after receiving enalapril monotherapy. Compared with pretreatment, GFR and RPF were improved significantly in group 2(P<0.05,P<0.01,respectively), RPF was improved in group 3(P<0.05)and renal vascular resistence (RVR) was decreased in group 2 and group 3(P<0.05, both).UMAE/Cr and UMGE/Cr decreased significantly in group 3(P<0.05, both) and UMAE/Cr, UMTE/Cr and NAG/Cr decreased significantly in group 1(P<0.05,all).In all groups,RBP/Cr tended to decrease after rceiving enalapril.One patient in group 1 developed hyperkalimia(7.8 mmol/L) but returned to normal after discontinuation of enalapril.Thus,in hypertensive patients with mild to
moderate renal dysfunction,treatment with enalapril may improve renal function. However,a smaller dose(10 mg/day)should be given with repeated assay of serum potasium and urinary protein excretion especially in patients with more ad vanced renal dysfunction.