Ammonia concentration in the renal veins in unilateral renal artery stenosis with hypertension.

We measured blood ammonia in pre-angioplasty samples from the renal veins, aorta and inferior vena cava of 15 patients with hypertension due to unilateral renal artery stenosis confirmed by arteriography. Patients with renal insufficiency or small kidneys were excluded. Mean ammonia values were microgram/dl: vein of affected kidney, 106.00 +/- 12.75; vein of unaffected kidney, 75.65 +/- 23.10; aorta 61.04 +/- 15.00; vena cava, 62.44 +/- 19.65. The value for the affected kidney was significantly higher than the other three values (p < 0.001). Mean +/- SD DTPA uptake (%) was 42.8 +/- 2.21 in the affected kidney and 56.53 +/- 3.64 in the unaffected kidney. This difference did not correlate significantly with that of the ammonia concentrations tau = -0.292).