| In the diagnosis and management of hypertension, the plasma renin activity assay (PRA) is considered a gold standard diagnostic tool. The assay relies on the quantitative assay of Anigiontensin I (Ang I), usually by RIA, after accumulation of Angiotensin I under specific conditions. We developed a highly sensitive, accurate and rapid LC-MS/MS based assay that would offer improvements in laboratory workflow while offering high-throughput capability suitable for a clinical laboratory. During development, we observed a substantial number of clinical samples that have strong degradation activity toward Ang I during generation. Using the capabilities of the mass spectrometer in union with a range of isotope labeled peptides, we have started to characterize the degradation products formed during generation. |
