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+/-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+/-1.86 pg/mL) compared to controls (1.40+/-0.15 pg/mL; P =0.0001). Patients with APSGN also had higher plasma ANP concentrations (41.67+/-27.99 pg/mL) than the controls (22.80+/-4.24 pg/mL; P =0.011). Plasma Rn concentrations were lower in patients (24.54+/-16.34 muU/mL) compared to controls (56.76+/-32.36 muU/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.