The effects of captopril on effective renal plasma flow and glomerular filtration rate were studied using a noninvasive radioisotopic method on individual kidneys in eight patients with renovascular hypertension and 12 patients with essential hypertension with various renin levels. Four patients with renovascular hypertension had unilateral while three had bilateral renal artery stenosis. The effective renal plasma flow and glomerular filtration rate were determined by using 131I-iodohippurate sodium and 99mTc-diethylenetriamine pentaacetic acid, respectively. Glomerular filtration rate and effective renal plasma flow were significantly reduced in the stenotic kidneys of patients with renovascular hypertension compared with values in nonstenotic kidneys (p less than 0.01). Treatment with captopril, 37.5 to 75 mg/day for 1 to 48 weeks, further reduced the glomerular filtration rate only in stenotic kidneys, and effective renal plasma flow increased in both kidney types. In two of the three renal hypertensive patients with bilateral renal artery stenosis, captopril produced a reversible azotemia that was unrelated to the fall in blood pressure, as evidenced by the lack of azotemia seen after a moderate blood pressure reduction induced by other antihypertensive medications. These results indicate that endogenous angiotensin II is essential in maintaining the glomerular filtration rate in stenotic kidneys and suggest that a reduction in glomerular filtration rate during captopril administration could indicate the presence of renal artery stenosis.

A 25-year-old woman with neurofibromatosis was admitted to our hospital for evaluation of hypertension. When she was 6 years old, she was diagnosed as having neurofibromatosis and XXX syndrome because of multiple café-au-lait spots, neurofibromas of the skin and mental retardation. Chromosome analysis revealed that her karyotype was 46, XX/47, XXX. Renal arteriography disclosed aneurysmal change and stenosis of the right renal artery. After right-side nephrectomy and aneurysmectomy, the kidney was autotransplanted in the left iliac fossa. Surgical procedure resulted in marked amelioration of the hypertension without medical treatment. Thus, aortorenal bypass and renal autotransplantation have emerged as the preferred revascularization operations. This is the first report of a chromosomal linkage between neurofibromatosis which is thought to be an autosomal dominant disease and the XXX syndrome.

No abstract