The role of the renin-angiotensin system in blood pressure regulation in normotensive animals and man.

The role of the renin-angiotensin system in the control of blood pressure in normal rodents, primates and man has been evaluated using inhibitors which block the system at various stages. Renin plays a major role in the maintenance of blood pressure under volume depletion. In subjects with a normal salt intake, the contribution of the renin-angiotensin system in maintaining blood pressure levels can be evaluated using angiotensin converting enzyme (ACE) inhibitors. The contribution of the renin-angiotensin system can now be evaluated more closely following the development of new substances which block the renin-angiotensinogen reaction. Available data strongly suggest that renin contributes to the maintenance of blood pressure levels in subjects with a normal salt intake, although to a lesser degree than in subjects on a low sodium intake. The renin-angiotensin system plays a role in the regulation of blood pressure levels in normal experimental animals and man--its importance depending on the state of sodium balance.