Enalapril and Losartan Augment Endogenous Nitric Oxide Release in Takayasu's Arteritis

Abstract

Prognosis in Takayasu's arteritis is limited owing to renovascular hypertension. The authors report a patient with Takayasu's arteritis who had been unilaterally nephrec tomized and presented with malignant hypertension due to renal artery stenosis. Hypertension was refractory to conventional antihypertensive treatment, and stenosis was not accessible by interventional angioplasty. Initiation of enalapril and losartan therapy was successful in improving blood pressure without deterioration of renal function due to ischemic failure. Antihypertensive treatment resulted in dramatically stimulated endogenous nitric oxide (NO) synthesis, while elevated plasma endothelin-1 levels were unchanged. Renovascular hypertension in Takayasu's arteritis is associated with an imbalance of vasoconstrictor peptide endothelin-1 and vasodilator peptide NO. Successful treatment of hypertension by enalapril or losartan results in improved endoge nous NO synthesis, which putatively counterbalances excessive vasoconstrictor actions and may retard the progression of renal failure.