[Pathophysiology of the renin-angiotensin system]

The renin angiotensin system is an important system for the regulation of blood pressure and salt and water homeostasis. As a pathogenetic factor it is involved in the development of several forms of renal hypertension and, furthermore, it participates in the pathogenesis of primary and secondary hypertension. The regulation of the activity of the system is under the control of neuronal and hormonal mechanisms and depends on blood pressure and plasma concentrations of sodium chloride. With the development of converting enzyme inhibitors and their vasodilator, diuretic and sympatholytic actions a new important antihypertensive principle for lowering blood pressure was found. In this context also local renin angiotensin systems which have been described for several tissues have to be discussed as a possible target of action for converting enzyme inhibitors.