Abstract
It is not clear why blood pressure increases in patients with chronic renal failure. The most widely advanced explanation is that such increases are due to extracellular volume expansion caused by decreased renal sodium and water excretion, but other factors may contribute. Activation of the renin–angiotensin system seems to be a pivotal factor, as indicated not only by measurements of plasma renin activity and serum aldosterone, but also by findings that angiotensin-converting enzyme (ACE) inhibitors have renal protective actions in patients with renal hypertension. In patients with renal failure, even normal values for plasma renin activity are inappropriately high for . . .