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 in investigation of pathogenesis of hypertension, oedema and other homeostatic disturbances, in differential diagnosis of hypertension and together with aldosterone determination also for differentiation of primary and secondary hyperaldosteronism.