Abstract 561: The ex vivo RAS-Fingerprint - A Novel Approach for the Biochemical Chatracterization of the Renin-Angiotensin-System in Clinical Samples
Angiotensin concentrations are affected by multiple molecular components including receptors and enzymes which might be either dissolved in plasma or attached to blood cells or endothelial surfaces throughout the body, giving rise to a concentration determining local enzymatic environment. This environment substantially changes during blood collection leading to a rapid and fundamental shift in angiotensin peptide levels. Therefore, a clearly defined and properly controlled sample stabilization procedure is essential for the accurate measurement of in vivo angiotensin peptide levels.
Surprisingly, standard samples collected by anti-coagulation with heparin can be used for analyzing the human RAS under well-defined steady-state conditions, allowing RAS-Fingerprint based conclusions about the activities of circulating enzymes involved in angiotensin metabolism. The mass spectrometry based measurements of in vivo RAS-Fingerprints (immediate sample stabilization) or heparin plasma derived ex vivo RAS-Fingerprints in plasma or whole blood provide unique insights into the physiology of the human RAS. RAS-Fingerprinting provides an integrated view about the activity of the enzymes involved in angiotensin metabolism in a plasma sample and therefore represents a powerful tool for characterization of the patient specific “Biochemical Hardware”, which determines angiotensin peptide levels in vivo.
The assay is compatible with undiluted plasma and whole blood and can be further applied to long-term stored frozen plasma samples. The utilization of RAS-Fingerprinting in clinical studies will substantially enhance our understanding of the human RAS and could lead to the development of personalized approaches for the treatment and prevention of cardiovascular diseases in the near future.
- © 2013 by American Heart Association, Inc.