Endothelin-1 in children with acute poststreptococcal glomerulonephritis and hypertension.

Background: Endothelin-1 (ET-1), the most potent vasoconstrictor peptide, is known to play a role in arterial hypertension. In patients with acute poststreptococcal glomerulonephritis (APSGN) an increase in the production of ET-1 is suspected due to damaged endothelium, platelet activation and increased thrombin production in the glomeruli. The aim of the present study was to investigate whether the levels of plasma ET-1 are elevated in children with APSGN. Furthermore, we examined the association between plasma ET-1 levels and blood pressure levels in the same children.

Methods: We studied 18 children (14 boys) with APSGN (mean age 7.44 to approximately 2.82 years). Fourteen healthy children served as controls. The following parameters were evaluated: plasma ET-1, plasma atrial natriuretic peptide (ANP), plasma renin (Rn), serum aldosterone (Aldo), creatinine clearance (Ccr) and fractional excretion of sodium (FENa).

Results: The mean plasma ET-1 concentrations were higher in patients with APSGN (3.39 to approximately 1.86 pg/mL) compared to controls (1.40 to approximately 0.15 pg/mL; P=0.0001). Patients with APSGN also had higher plasma ANP concentrations (41.67 to approximately 27.99 pg/mL) than the controls (22.80 to approximately 4.24 pg/mL; P=0.011). Plasma Rn concentrations were lower in patients (24.54 to approximately 16.34 microU/mL) compared to controls (56.76 to approximately 32.36 microU/mL; P=0.027). A positive correlation was found between ET-1 plasma concentrations and the height of systolic or diastolic blood pressure (r=0.57, P=0.013 and r=0.53, P=0.023, respectively).

Conclusions: Our results suggest that increased plasma ET-1 concentrations may play an important role in the pathogenesis of hypertension in children with acute poststreptococcal glomerulonephritis.