The aim of this study is to evaluate and compare the activity of the sympathetic nervous system and the renin-angiotensin system in patients with unilateral or bilateral renovascular hypertension. Plasma noradrenaline (plNA) levels and plasma renin activity (PRA) were measured simultaneously in blood samples obtained both from a peripheral vein and from the renal veins, during catheterization of the venous cava system, in 17 patients with unilateral (group A) and in 9 patients with bilateral renal artery stenoses (group B).
Results: peripheral plNA levels were elevated in 6/17 patients of the group A and 3/9 patients of the group B, while in the remaining 11/17 and 6/9 were normal, respectively. The comparison of plNA levels between the renal veins showed that in both groups plNA levels were higher in the renal vein of the ischaemic (group A) or the more ischaemic kidney (group B), and the difference was statistically significant. Renal vein renin ratio was above 1.5 in both groups. Renin hypersecretion from the ischaemic or the more ischaemic kidney compared to renin suppression from the normal or the less ischaemic kidney showed statistically significant difference.