The Distribution of Intrarenal Blood Flow in Normal and Hypertensive Man

Observations were made on eight normotensive subjects and on 12 patients with essential hypertension to determine whether the intrarenal distribution of blood flow is altered in essential hypertension. Dye-dilution curves were recorded across the renal vascular bed and a set of integral transformations, developed by Gomez, was used to determine distribution of blood flow per unit renal blood volume across the renal vascular bed from dye-dilution curves. Observations also were made on two hypertensives and two normotensives during administration of norepinephrine. The distribution of specific blood flow and the functional renal blood volume in the right kidney of patients with essential hypertension were comparable to those in normal subjects, but the mean specific blood flow was reduced in essential hypertension. Failure to demonstrate altered distribution of specific blood flow in essential hypertension indicated an absence of focal reductions in renal blood flow and that blood flow is reduced uniformly throughout the renal vascular bed in essential hypertension. This reduction in specific renal blood flow is attributed to arteriolar vasoconstriction.