Objective—To determine whether the angiotensin
converting enzyme inhibitor enalapril would lower
systemic arterial and glomerular capillary pressure
and reduce the magnitude of renal injury in a canine
model of renal insufficiency.
Animals—18 adult dogs that had renal mass reduced
by partial nephrectomy.
Procedure—After surgical reduction of renal mass
and baseline measurements, dogs in 2 equal groups
received either placebo (group 1) or enalapril (0.5
mg/kg, PO, q 12 h; group 2) for 6 months.
Results—Values for systemic mean arterial blood
pressure determined by indirect and direct measurement
after 3 and 6 months of treatment, respectively,
were significantly lower in group 2 than in group 1.
During treatment, monthly urine protein-to-creatinine
ratios were consistently lower in group 2 than in
group 1, although values were significantly different
only at 3 months. At 6 months, significant reduction
in glomerular capillary pressure in group 2 was detected,
compared with group 1, but glomerular filtration
rate in group 2 was not compromised. Glomerular
hypertrophy, assessed by measurement of planar surface
area of glomeruli, was similar in both groups.
Glomerular and tubulointerstitial lesions were significantly
less in group 2, compared with group 1.
Conclusions and Clinical Relevance—Data suggest
that inhibition of angiotensin converting enzyme was
effective in modulating progressive renal injury, which
was associated with reduction of glomerular and systemic
hypertension and proteinuria but not glomerular
hypertrophy. Inhibition of angiotensin converting
enzyme may be effective for modulating progression
of renal disease in dogs. (Am J Vet Res 2003;64:321–327)