INCREASED PLASMA ENDOTHELIN CONCENTRATION IN ATHEROSCLEROTIC RENOVASCULAR HYPERTENSION

The aim was to investigate circulating levels of immunoreactive endoth elin (ir-ET) in atherosclerotic renovascular hypertension (RVH), and t o assess the role of the kidneys in its overall plasma concentration. We studied 16 hypertensive patients with renal artery stenosis evidenc ed by angiography and admitted to hospital for the diagnostic evaluati on of RVH by renal vein plasma renin activity (PRA) determinations. Th e right femoral vein was catheterized to simultaneously measure PRA an d ir-ET in both renal veins and inferior vena cava below the origin of the renal veins. RVH was present in 9 patients as indicated by diagno stic PRA renal vein ratios and the remaining 7 patients were considere d to have essential hypertension (EH). Patients with RVH showed a mark ed increase in systemic plasma ir-ET concentration (10.3 +/- 0.9 pg/ml ) as compared to hypertensives without RVH (6.2 +/- 0.6 pg/ml, p < 0.0 05). Despite a significant increase of PRA in the vein of the ischemic (IK) versus the contralateral (CK) kidney in patients with RVH, no si gnificant differences in ir-ET concentration were observed between bot h kidneys. These results indicate that patients with RVH have increase d circulating levels of ir-ET. However, the higher systemic plasma ir- ET do not arise from the renal circulation, since plasma ir-ET is sign ificantly higher in systemic circulation than in renal veins.