Role of glomerular filtration rate in the impaired sodium and water excretion of patients with the nephrotic syndrome.
Hemodynamic and hormonal factors were monitored in nine patients with nephrotic syndrome who were evaluated relative to their capacity to excrete a 20-mL/kg water load (normal greater than 80%). In five "nonexcretor" patients (37% of water load excreted in five hours), as compared to four normal excretors (105% of water load excreted in five hours; P less than .01 v nonexcretors), neither BP (131/88 v 119/79 mm Hg), pulse (74 v 77 beats/min), cardiac index (3.7 v 3.1 L/min/m2), pulmonary wedge pressure (9.3 v 7.3 mm Hg), systemic vascular resistance (1537 v 1254 dynes-sec-cm-5), nor plasma volume (41.3 v 40.1 mL/kg) were different. Similarly, plasma renin activity (2.6 v 3.7 ng/mL/h), plasma aldosterone (12 v 10.9 ng/dL), and plasma norepinephrine (403 v 312 pg/mL) were not different between nonexcretor v excretor patients with nephrotic syndrome. Plasma vasopressin concentrations were also similar both before (3.1 +/- 0.8 v 2.4 +/- 1.2 pg/mL) and during the water load (0.9 +/- 0.3 v 1.0 +/- 0.4 pg/mL). Inulin clearances, however, were lower in the nonexcretor v the excretor nephrotic patients (37 v 78 mL/min/1.73 m2; P less than .02) and correlated with water excretion (r = .68; P less than .05). Head-out water immersion increased sodium (40 to 110 microEq/min; P less than .01) and water excretion (37% to 82%; P less than .025) in the nonexcretors; the improvement correlated with the increase in inulin clearance during immersion (r = .70; P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)
D000293:Adolescent; D000328:Adult; D000450:Aldosterone / Q000097:blood; D001127:Arginine Vasopressin / Q000097:blood; D001834:Body Water / Q000378:metabolism*; D005260:Female; D005919:Glomerular Filtration Rate; D006439:Hemodynamics; D006801:Humans; D007101:Immersion; D007444:Inulin / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009404:Nephrotic Syndrome / Q000097:blood / Q000378:metabolism / Q000503:physiopathology* / Q000652:urine; D009638:Norepinephrine / Q000097:blood; D010953:Plasma Volume; D012083:Renin / Q000097:blood; D012964:Sodium / Q000652:urine*
D001127:Arginine Vasopressin; D000450:Aldosterone; D007444:Inulin; D012964:Sodium; D012083:Renin; D009638:Norepinephrine