1. In normal man, in deoxycorticosterone/salt hypertension, and in renal artery stenosis, an inverse relationship between plasma renin activity (PRA) and renin-substrate (RS) is found.
2. PRA and RS were found to be inversely related in primary aldosteronism and in anephric patients.
3. In malignant hypertension, by contrast, the highest PRA levels were associated with the highest RS levels.