[Levels of 1,25-dihydroxyvitamin D3 concentration in renal venous blood serum of patients with renovascular hypertension caused by unilateral renal artery stenosis].

UNLABELLED: Functionally significant, unilateral renal artery stenosis is characterized by reduced renal perfusion and lateralization of both excretory and endocrine function. The present study aimed to assess the influence of unilateral renal artery stenosis on plasma 1,25-dihydroxyvitamin D3 level. In sixteen patients (10 males and 6 females) with unilateral renovascular hypertension blood samples for estimation of plasma renin activity (PRA) and 1,25-dihydroxyvitamin D3 concentration were withdrawn from the renal vein of the ischaemic and normal kidney, from the femoral artery and from the vena cava inferior distally to the orifices of renal veins. Significantly elevated PRA (20.1 +/- 4.52 ng/ml/h vs 6.0 +/- 1.76 ng/ml/h, p < 0.005) but significantly reduced level of 1,25-dihydroxyvitamin D3 (99.25 +/- 4.8 pmol/l vs 115.75 +/- 6.7 pmol/l, p < 0.05) were found in renal vein blood of the ischaemic kidney as compared with the respective values of the normal kidney. No significant correlation was found between PRA and 1.25-dihydroxyvitamin D3 irrespective of the site of blood withdrawal.

CONCLUSION: Renal ischaemia seems to exert a suppressive effect on 1,25-dihydroxyvitamin D3 synthesis by the kidney.