The renin-angiotensin system in the control of systemic arterial pressure.

The renin-angiotensin system through its active octapeptide, angiotensin II, has an important role in systemic arterial pressure control. Angiotensin II is a potent direct vasoconstrictor and is also the main regulator of aldosterone secretion. The complete analysis of the role of angiotensin II has to take into account the prevailing sodium balance for a given level of angiotensin II and also its indirect action upon the sympathetic nervous system as well as other hormonal systems. A number of studies have provided evidence for an important role for the renin-angiotensin system in renovascular hypertension, malignant and severe hypertension, as well as in mild to moderate forms of essential hypertension.