title: A study of the renal handling of water in lipoid nephrosis.
abstract: Children with lipoid nephrosis were studies during clinical relapse and after complete remission. As expected, the calculated serum oncotic pressure was reduced severely from the remission value of 28.6 +/- 0.9 mm Hg to 15.4 +/- 1.1 (P less than 0.005) during relapse. Although no apparent change in plasma volume was noted using the volume of distribution of labeled human albumin, calculated plasma volume was reduced 13 +/- 8% during relapse when estimated from changes in hematocrit. After a water load, the ability to excrete water was markedly blunted during relapse. The clearance of solute-free water (CH2O) was 0.9 +/- 0.8 ml/min during relapse, compared with 3.6 +/- 0.6 ml/min during remission (P less than 0.005). In addition, there was a reduced maximal urinary concentrating ability during relapse in four of the six patients examined. Mean urine osmolality for the group during relapse was 778 +/- 82 mOsm/kgH2O and 991 +/- 71 during remission (P less than 0.05). The demonstrated alteration in nephron function during relapse of nephrotic syndrome could result from either (1) a decrease in the amount of sodium delivered to the ascending limb of the loop of Henle because of increased proximal reabsorption or (2) a change in the intrinsic characteristics for sodium reabsorption in that segment. Although this observation does not prove that proximal reabsorption is increased, it suggests a common underlying mechanism for altered nephron function in all of the major edema-forming conditions.
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005919:Glomerular Filtration Rate; D006801:Humans; D007671:Kidney Concentrating Ability; D009402:Nephrosis, Lipoid / Q000503:physiopathology*; D012075:Remission, Spontaneous; D012964:Sodium / Q000378:metabolism; D014867:Water / Q000378:metabolism*
chemical_list: D014867:Water; D012964:Sodium