Plasma Renin Activity Aldosterone Concentration Research Articles

Hormonal effects of the diuretic xipamide in healthy men

The effect of xipamide on plasma alpha-atrial natriuretic peptide and the renin-aldosterone-kallikrein system have been studied in 12 healthy men, using a double-blind cross-over design. After a run-in period on placebo of 1 week, the subjects were treated with either placebo (n = 6) or xipamide 20 mg once daily (n = 6) for 16 weeks and were then switched to the alternative medication for another 16 weeks. The plasma concentration of alpha-atrial natriuretic peptide fell after 1 week of xipamide administration and increased during prolonged xipamide administration but remained reduced. The changes in plasma alpha-ANP observed after 1 week of xipamide were negatively correlated with the changes in hematocrit and hemoglobin. Plasma renin activity (PRA), aldosterone concentration (PAC), and urinary excretion of aldosterone and kallikrein increased after 1 week of xipamide administration, levelled off during the second and fourth weeks, but remained elevated during further prolonged xipamide administration for 16 weeks. The xipamide-induced changes in PRA and PAC were positively correlated with the changes in the hematocrit and hemoglobin. The changes in plasma renin, aldosterone, and alpha-atrial natriuretic peptide during xipamide administration may be related to diuretic-induced volume contraction.

Plasma atrial natriuretic peptide and the renin-aldosterone system during long-term administration of the diuretic xipamide in man

We have studied the effect of xipamide on plasma alpha-atrial natriuretic peptide and the renin-aldosterone-kallikrein system in twelve healthy men, using a double-blind cross-over design. After a run-in period on placebo for 1 week the subjects were treated with either placebo (n = 6) or xipamide 20 mg once daily (n = 6) for 16 weeks and were then switched to the alternative medication for another 16 weeks. The plasma concentration of alpha-atrial natriuretic peptide fell after 1 week of xipamide administration and increased during prolonged xipamide administration but remained suppressed. The changes in plasma alpha-ANP observed after 1 week of xipamide were negatively correlated with the changes in haematocrit and haemoglobin. Plasma renin activity (PRA), aldosterone concentration (PAC), and urinary excretion of aldosterone and kallikrein increased after 1 week of xipamide administration, levelled off during the second and fourth weeks, but remained elevated during further prolonged xipamide administration for 16 weeks. The xipamide-induced changes in PRA and PAC were positively correlated with the changes in the haematocrit and haemoglobin. Our data suggest that the changes in plasma renin, aldosterone, and alpha-atrial natriuretic peptide during xipamide administration may be related to diuretic-induced volume contraction.

Lisinopril in hypertensive patients with and without renal failure.

Lisinopril (MK521), a lysine analogue of enalaprilic acid, the bioactive metabolite of enalapril, has a longer half-life than enalaprilic acid, and is excreted unchanged in the urine. Its kinetic profile and antihypertensive and hormonal effects have been investigated in an open study in 3 groups each of 6 hypertensive patients, with normal, moderate and severe impairment of renal function. Serum drug level, blood pressure, converting enzyme activity (CEA), plasma renin activity (PRA), aldosterone concentration (PAC), and serum potassium and creatinine were measured during 1 week following a single oral dose and subsequently following 8 daily doses of 5 mg lisinopril. Accumulation of lisinopril was found in the severe renal failure group. CEA was suppressed to less than 10% of its initial value from 4 to 24 h after the initial dose in all three groups, and the suppression was more marked and lasted longer in patients with severe renal failure. An inverse correlation was found in all patients between log serum lisinopril concentration and log CEA. Lisinopril lowered blood pressure in all three groups over 24 h. PRA rose and PAC fell similarly in the groups. Serum potassium increased in the renal failure groups and creatinine remained unchanged in all groups. Thus, when lisinopril 5 mg is given daily to patients with severe renal failure it may accumulate. The high serum lisinopril concentration does not cause an excessive antihypertensive effect. In patients with severe renal failure, adjustment of the dose or the dosing frequency to the degree of renal failure is recommended to avoid administration of doses in excess of those required to achieve adequate inhibition of converting enzyme.