Angiotensin I
System renin-angiotensin is one of very important regulation mechanism of electrolyte, volume and pressure homeostasis. Angiotensin I is one of the components of angiotensin cascade and the rate of its generation (plasma renin activity - PRA) reflects well the overall activity of this system. PRA determination can be used an aid in diagnosis and differential diagnosis of primary and secondary hyperaldosteronism and hypoaldosteronism.