The authors assessed in 20 subjects with mild or medium severe arterial hypertension basal and stimulated values of plasma renin activity (PRA) and aldosterone before onset of treatment and after 6-week therapy with enalapril (ENAP KRKA) or metoprolol (Vasocardin Slovakofarma). PRA and aldosterone secretion was stimulated by a vertical position and by administration of 40 mg furosemide by the i.v. This test proved suitable for assessment of secondary arterial hypertension in different forms of primary hyperaldosteronism and for expressing suspicion of renovascular hypertension and hypertension with affection of the renal arteries resp. Based on PRA levels, arterial hypertension can be divided into normorenin, high-renin and low-renin hypertension. This classification is, however, of no value for selection of treatment and the prognosis of hypertension. Each level of PRA can be associated with three different aldosterone levels. PRA and aldosterone did not correlate with urinary K, Na excretion nor with blood pressure. During treatment with ACE inhibitor PRA rose while basal as well as stimulated aldosterone levels declined. After administration of betablockers basal as well as stimulated PRA and aldosterone levels declined.

Keywords: Adult; Aldosterone /blood/; Cross-Over Studies; Enalapril /therapeutic use/; Female; Humans; Hypertension /blood/; Male; Metoprolol /therapeutic use/; Middle Aged; Renin-Angiotensin System