Local levels of
angiotensin peptides depend on their rates of production and degradation, which induce proatherogenic or atheroprotective effects. Here, we reveal the kinetics of Angiotensin-I metabolism in paired early and advanced atherosclerotic lesions.
2">Methods
Lesions were spiked with labeled Ang-I* and supernatants withdrawn after 0, 10, 20, 40 and 80 min. The concentration of produced Ang-II*, Ang-III*, Ang-IV* and Ang-(1–7)* peptides were measured using multiple reaction monitoring mass spectrometry coupled to ultra-performance liquid chromatography, normalized to tissue weight and initial [Ang-I*].
Results
Ang-(1–7)* was the major angiotensin peptide produced, showing increased levels in both tissue types, with 2–3 fold lower levels in advanced compared to early lesions. In contrast, Ang-II* was 2–3 fold higher in advanced compared to early lesions, showing a decrease between 0 and 40 min then an increase at 80 min in both tissue types. The levels of Ang-IV were stable in both tissue types across all time points. Finally, Ang-III was non-detectable in both lesions across all time points.
Conclusion
Our results suggest that progression of atherosclerosis depends on the increased levels of Ang-II along with the decreased levels of Ang-(1–7), which supports the use of Ang-(1–7) along with Angiotensin type-1 receptor (AT1R) blockers.
