Figure 1.

The renal-mean arterial pressure (MAP) set-point model as proposed by Guyton et al. [13–15]. (a) Basic renal-body fluid feedback mechanism for long-term regulation of blood pressure and body fluid volumes. (b) Normalized urinary sodium excretion is plotted as a function of the MAP to show the pressure natriuresis relationships, at different sodium intake levels, corresponding to the normal condition (acute renal function curves 1, 2, and 3 and chronic renal function curve (I)) and to a mild hypertension condition (chronic renal function curve (II) ). See further details in text.