Figure 4. Effect of ACE inhibitors on blood ACE activity.

Serum samples (1/5 dilution in PBS) from pool of 10 healthy volunteers (control) and from patient # 27 (arrowed in Fig. 1 C) were incubated with different concentration of ACE inhibitors: short –enalaprilat (A) and long –teprotide (B). Residual ACE activity was determined with two ACE substrates (and ZPHL/HHL ratio) as in Fig. 2. Data presented are mean ± SD of 2–3 independent experiments in duplicates). * p<0.05 vs. control serum.