1. Patients with cadaveric renal transplants and plasma creatinine less than 177 μmol/l who had their own kidneys removed were studied.
2. The renin—angiotensin system appeared to behave in a normal fashion in response to alterations in sodium intake and posture.
3. The renin—angiotensin system had no major role in the establishment or maintenance of hypertension.
4. Mean arterial pressure was directly related to expansion of the extracellular fluid volume.