Innovative Methodology Novel sandwich ELISA for human angiotensinogen

recently reported that urinary excretion rates of angiotensinogen (UAGT) provide a specific index of intrarenal renin-angiotensin (ANG) system (RAS) status in ANG II-dependent hypertensive rats. When this is shown to be applicable to human subjects, a diagnostic test to identify those hypertensive patients most likely to respond to an RAS blockade could provide useful information to allow a mechanis-tic rationale for selection of an optimized approach to treatment of hypertensive patients. However, simple and accurate methods to measure human angiotensinogen (hAGT) are unavailable. For future studies of human subjects, we developed antibodies and a sensitive and specific quantification system for hAGT using a sandwich ELISA. We raised two antibodies against hAGT: a mouse monoclonal anti-body and a rabbit polyclonal antibody. The standard curve of this ELISA exhibited a high linearity (0.31–20 ng/ml). The correlation coefficient was 0.99. Plasma angiotensinogen concentrations o