Adrenomedullin and nitrite levels in children with minimal change nephrotic syndrome

Abstract

Nitric oxide (NO) serves many functions within the kidney, and recent evidence suggests that NO contributes to glomerular injury. Adrenomedullin (AM) is a novel hypotensive peptide originally isolated from human pheochromocytoma. Recent studies showed that plasma AM concentrations correlated with the extent of proteinuria. We have examined the possible role of these two agents by studying plasma and urinary total nitrite (NO-2 + NO-3) and AM levels in children with minimal change nephrotic syndrome (MCNS). In comparison with healthy controls, children with MCNS had increased urinary nitrite excretion (micromol/mg urinary creatinine), irrespective of whether the disease was in relapse or remission (3.2+/-0.2 in relapse, n=13; 1.9+/-0.3 in remission, n=12; 1.0+/-0.2 in controls, n=10, P<0.05). Plasma nitrite levels (micromol/l) were high in relapse compared with controls (53.2+/-8.7 vs. 32+/-4.0, P<0.05). Plasma AM levels (pmol/ml) were decreased in relapse (27.6+/-1.4 in relapse, 43.3+/-1.2 in remission, 41.5+/-1.6 in controls, P<0.05). Urinary AM levels (pmol/mg urinary creatinine) were significantly higher in relapse than in remission and in controls (156+/-43 in relapse, 56+/-18 in remission, 36+/-16 in controls, P<0.05). Our data indicate that NO may play a role in mediating the clinical manifestations of MCNS in children. However, changes in AM levels may be the result of heavy proteinuria.

NOx (nitrite/nitrate) in patients with pediatric nephrotic syndrome

“…Trachtman et al also reported that patients with MCNS had increased urinary nitrite excretion regardless of whether the disease was in relapse or remission [6]. The present data concerning NOx in serum support the results by Balat et al and Trachtman et al [5,6]. From our studies with immunostaining, no nitrotyrosine, iNOS, or eNOS were dyed in the case that showed a particularly high NOx in serum.…”

“…In comparison with healthy controls, children with MCNS had increased urinary nitrite excretion. Plasma nitrite levels were high in relapse compared with controls [5]. Trachtman et al also reported that patients with MCNS had increased urinary nitrite excretion regardless of whether the disease was in relapse or remission [6].…”

Surface markers of platelet function in idiopathic nephrotic syndrome in children

“…NO is also suggested to inhibit platelet activation, due to an increase in cytosolic cAMP concentration [34,35,36]. We have not found any study directly related to this problem, although there are studies detecting increased NO production in INS [37]. Further studies on the role of NO in platelet function in INS are clearly needed.…”

Increased nitric oxide production by T- and B-cells in idiopathic nephrotic syndrome

“…As a result, efforts have been made to identify this VPF as well as to understand the mechanism(s) for its increased release [2]. It has also been suggested that nitric oxide (NO), a typical free-radical gas synthesized from L-arginine by three isoforms of nitric oxide synthase (NOS), may be a VPF, leading to proteinuria in INS [12][13][14]. This hypothesis is based on the fact that NO has many physiological functions within the kidney, such as the regulation of vascular tone, renal hemodynamics, and modulation of fluid and electrolyte transport [15,16].…”