Chymase-Dependent Generation of Angiotensin II from Angiotensin-(1-12) in Human Atrial Tissue
Figure 2
Ang-(1-12) metabolism by human atrial tissue.
The metabolism of 125I-Ang-(1-12) by plasma membrane isolated from human atrial tissues was analyzed by HPLC coupled to an inline BioScan γ-detector. The 125I-Ang-(1-12) was incubated with human plasma membrane for 60 min at 37°C with or without the inhibitor cocktail and the metabolites were separated by HPLC. A: Chromatograms represent the hydrolysis of 125I-Ang-(1-12) in the presence of all RAS inhibitors (All RAS inhibitor group containing lisinopril, SCH39370, MLN-4760, chymostatin, bestatin, amastatin, benzyl succinate, and PCMB). B: Hydrolysis of 125I-Ang-(1-12) in the absence of all RAS inhibitors cocktail (No RAS inhibitors group containing only bestatin, amastatin, benzyl succinate, and PCMB). C: Hydrolysis of 125I-Ang-(1-12) in the presence of the inhibitor cocktail that lacks only Lisinopril (No lisinopril inhibitor group containing all inhibitors as described in “A” except ACE inhibitor). D: Hydrolysis of 125I-Ang-(1-12) in the presence of inhibitor cocktail that lacks only chymostatin (No chymostatin group containing all inhibitors as described in “A” except chymase inhibitor). Before adding the 125I-Ang-(1-12), the plasma membrane was pre-incubated with inhibitors (each added at a dose of 50 µM) for 15 min at 37°C. The arrow indicates the retention time of 125I-Ang-(1-12) and its metabolic products. HPLC results are representative of three or more separate metabolism experiments for each human sample.