Evaluation of a technique of inducing hypertensive renal insufficiency in cats.

OBJECTIVE

To compare 2 techniques of inducing combined renal insufficiency and systemic hypertension in cats.

ANIMALS

22 cats 6 to 12 months of age.

PROCEDURES

Cats were randomly assigned to 1 of 3 groups. Control (C) group cats had 2 intact kidneys, remnant kidney (RK) group cats underwent unilateral partial renal infarction and contralateral nephrectomy, and remnant-wrap (W) group cats underwent unilateral partial renal infarction and partial abtation and wrapping of the contralateral kidney. Systemic arterial blood pressure (BP) was measured continuously by use of implanted radiotelemetric devices. Renal function was assessed via determination of glomerular filtration rate, measurement of serum creatinine and BUN concentrations, and determination of urine protein-to-creatinine ratio (UP/C). Serum aldosterone concentration and plasma renin activity were measured on day 75.

RESULTS

Systolic BP was significantly higher in groups RK and W than in group C, and systolic BP was significantly higher in group W than in group RK. Serum aldosterone concentration and plasma renin activity were significantly higher in group W, compared with groups C and RK. Glomerular filtration rate was significantly lower in groups RK and W, compared with group C. Histologic indices of renal injury and UP/C were significantly higher in group W, compared with groups C and RK.

CONCLUSIONS AND CLINICAL RELEVANCE

Hypertensive renal insufficiency in group W was characterized by marked sustained systemic hypertension, decreased renal function, proteinuria, activation of the renin-angiotensin-aldosterone axis, and renal structural injury. Results support the hypothesis that marked systemic hypertension, activation of the renin-angiotensin-aldosterone axis, and proteinuria may damage the kidney of cats with preexisting renal insufficiency.