The effect of a 6-week treatment with the
calcium channel blocker nitrendipine or the
angiotensin converting enzyme inhibitor enalapril on blood pressure,
albuminuria, renal hemodynamics, and morphology of the nonclipped kidney was studied in rats with two-kidney, one
clip renovascular hypertension. Six weeks after clipping of one renal artery, hypertensive rats (178 +/- 4 mm Hg) were randomly assigned to three groups: untreated hypertensive controls (n = 8),
enalapril-treated (n = 8), or
nitrendipine-treated (n = 10).
Sham-operated rats served as normotensive controls (128 +/- 3 mm Hg, n = 8). After 6 weeks of treatment, renal hemodynamics (glomerular filtration rate and renal plasma flow) were measured in the anesthetized rats. Renal tissue was obtained for determination of glomerular size and
sclerosis.
Enalapril but not
nitrendipine reduced blood pressure significantly. After 6 weeks of
therapy, glomerular filtration rate was not different among the studied groups. Renal plasma flow increased, but
albumin excretion and glomerulosclerosis did not change after
enalapril treatment. In contrast, in the
nitrendipine-treated group
albuminuria increased from 12.8 +/- 2 progressively to 163 +/- 55 compared with 19.2 +/- 9 mg/24 hr in the hypertensive controls. Furthermore, glomerulosclerosis index was significantly increased in the
nitrendipine-treated group compared with the hypertensive controls (0.38 +/- 0.1 versus 0.13 +/- 0.04). In addition, glomerular size was higher in the
nitrendipine-treated group (14.9 +/- 0.17 10(-3) mm2) but lower in the
enalapril-treated group (11.5 +/- 0.15 10(-3) mm2) compared with the hypertensive controls (12.1 +/- 0.17 10(-3) mm2).(ABSTRACT TRUNCATED AT 250 WORDS)