Plasma atrial natriuretic peptide and endothelin levels in acute poststreptococcal glomerulonephritis

Plasma levels of atrial natriuretic peptide (ANP) and of endothelin (ET) were significantly elevated (87.7 +/- 13.9 pg/ml and 79.7 +/- 10.8pg/ml, respectively) during the acute phase of acute poststreptococcal glomerulonephritis (APSGN). Plasma renin levels were normal, fractional excretion of sodium (FENa) was 0.5 +/- 0.1% and creatinine clearance (CCr) averaged 82.2 +/- 18.3 ml/min per 1.73 m2. In the recovery phase of the disease (n = 12), levels of ANP (23.6 +/- 6.7 pg/ml) and ET (43.1 +/- 2.4 pg/ml) fell and were not significantly different from those measured in 11 control subjects. FENa increased to 1.3 +/- 0.1% and CCr to 113.5 +/- 12.1 ml/min per 1.73 m2 (all values mean +/- standard error). ANP did not correlate with PRA, blood pressure, CCr or FENa. There was an inverse relationship between the ET level and FENa in the acute phase of the disease (r = 0.489, P < 0.05), but no significant correlation between ET and blood pressure, PRA, CCr or ANP was found. We suggest that, despite the sodium retention, the increased ANP level in APSGN indicates unresponsiveness of the kidneys to ANP; the increased ET levels may contribute to this.