131I]Hippuran renography in normal subjects and in patients with essential hypertension.

Seventeen normal subjects and 21 patients with essential hypertension were examined by [131I]hippuran renography. Both groups were studied twice on the same day, first in a state of moderate dehydration and then after rehydration. From these data, four sets of reference intervals were established for several renographic parameters. Differences between the two groups were defined. The most impressive observation was a greater functional disparity between the two kidneys of one individual in the group of hypertensive patients, particularly when in a state of moderate volume depletion. This was reflected in a greater variance of certain kidney-to-kidney ratios derived from the renographic tracings. This article presents basic data to be utilized in clinical renography, as described in an accompanying article.