The value of the diagnostic criteria of plasma renin activity (PRA) for unilateral renal ischemia was investigated in hypertensive rabbits with bilateral renal artery stenosis.
Hypertension was produced by staged constriction of right renal artery with one of three different clips followed by left renal artery constriction with a clip of the smallest diameter. Eighteen of 21 rabbits thus operated developed sustained hypertension.
In all 21 rabbits, PRA was determined in three different blood veins, L: left renal vein renin, R: right renal vein renin and IVC: distal vena cava renin. Three PRA patterns, L>RIVC (A type), L, R>IVC (B type) and R>LIVC (C type), were observed.
A significant reduction in blood pressure after unilateral removal of the more severely affected kidney was obtained in those with A type PRA pattern. Two of 4 rabbits with B type PRA pattern showed some decrease in blood pressure after unilateral nephrectomy in those with renin ratio of 1. 4 between the venous blood samples obtained from unoperated kidney and distal vena cava.
The observation was in accord with the clinical experience, that patients with A type PRA pattern were surgically curable in renovascular hypertension.