A new bioassay method for measurement of angiotensin II using isolated bovine adrenal cells: clinical application on the plasma renin activity.

A new bioassay method for measurement of angiotensin II was clinically applied to determine the plasma renin activity (PRA) in normal subjects and hypertensive patients. Angiotensin II was extracted by a modified procedure reported by Boucher et al. Levels of angiotensin II extracted from 17 blood samples were independently determined by our new bioassay method and the rat pressor assay. The new Imethod could determine the minimum level of PRA of 0.25 ng. According to the new bioassay method, mean PRA levels for 9 normal subjects were 63.6±48.7 ngfdl, 177.7± 99.3 ngfdl, and 172.3±124.3 ngfdl at 1 hr after supine position, 1 hr after upright position with administration of 80 mg furosemide, and 2 hrs after upright position, respectively. Correlation coefficient of PRA levels between two bioassay methods was r=0.85 (p=0.005). It was concluded that the new method for PRA might be more reliable and much simpler than the rat pressor assay for clinical applications. PRA, Angiotensin II, Bioassay, Isolated cells.