Figure 1: Simulations of Ace gene titration and progressive ACE inhibition. (A), ACE gene titration. Mild quantitative changes in the expression of ACE do not affect plasma Ang II level or BP because of the concomitant changes in the level of Ang I. However, plasma bradykinin (BK) level changes with changes in ACE expression. The levels expected in association with the human I/D polymorphism are shown. (B). Effects of ACE inhibition. When inhibition is virtually complete, the simulation shows that: 1) Ang I levels are high and plateaued; 2) Ang II levels are low; 3) BK levels are increased by the virtual absence of ACE; and 4) BP is substantially lowered. (Adopted from reference 8 with permission).