Figure 7.

Depiction of the hypothesis that increasing vasodilatory action of diuretics inhibiting tubulo-arteriolar feedback can account for the decrease in gradient of the pressure-natriuresis line brought about by these drugs. A constant degree of afferent arteriolar dilatation leads to a parallel downward shift of the pressure-natriuresis line (as shown in Figure 6). The stack of pressure-natriuresis lines depicted here for diuretics arises because the degree of afferent arteriolar dilatation is hypothesized to depend upon inhibition tubulo-arteriolar feedback, which in turn depends upon the sodium excretion rate.