Biological significance of active and inactive renin in hypertensive patients

The significance of active and inactive renin was investigated by comparison of an in vitro assay of active, total and inactive plasma renin concentration (APRC, TPRC, IPRC) and plasma angiotensin II concentration (PA II) with an in vivo change in mean arterial pressure (MAP) produced by angiotensin antagonism with saralasin and by angiotensin converting enzyme blockade with captopril. A significant relationship between the changes in MAP during saralasin and captopril with the pre-treatment level of APRC, TPRC and PA II were found; while the pre-existing level of inactive renin was not a predictor for the hypotensive effect of saralasin and captopril. During captopril and saralasin significant increases in TPRC and APRC were found and no change in IPRC.