Failure of saralasin to predict a response to surgery in renovascular hypertension.

Arteriography in two patients with renovascular hypertension suggested fibromuscular hyperplasia, mainly affecting the right renal artery. When saralasin was infused intravenously there was no fall in blood-pressure in either patient. However, both had a raised renal-vein plasma-renin activity on the affected side, relative to the unaffected kidney. Auto-transplantation resulted in a sustained reduction in arterial pressure in both patients. A negative saralasin test should not necessarily exclude further investigation of young patients with severe hypertension.