Segmental renal vein sampling for renin.

Segmental renal vein sampling was performed in 25 hypertensive patients. In those with no arteriographic abnormalities or stenosis of only the main renal artery, renin levels from segmental veins were the same as those from the ipsilateral main renal vein. In patients with an infarction of a renal segment or stenosis of a segmental renal artery, the renin level from the corresponding segmental vein was often much higher than that from the main renal vein. Segmental vein sampling may reveal a significant source of renin production not apparent in samples from the main renal vein.