TY - JOUR
T1 - A Furosemide Test in the Functional Evaluation of the Human Nephron in Vivo
AU - BARTOLI, ETTORE
AU - SATTA, ANDREA
AU - FAEDDA, ROSSANA
AU - OLMEO, NINA A.
AU - SOGGIA, GIOVANNI
AU - BRANCA, GIANFRANCO
PY - 1983/1
Y1 - 1983/1
N2 - Abstract: A new renal function test was developed based upon the pharmacologic effects of furosemide to quantify separately the rates of electrolyte and water reabsorption by different segments of the human nephron in vivo. Since furosemide impairs active NaCl transport to Henle's loop and the attendant hypertonicity of the interstitium, osmotic water reabsorption from collecting ducts decreases and the unreabsorbed volume is lost into the urine, causing a rise in flow rate. This volume is computed from the difference in urine flow rate during furosemide with respect to that previously measured during maximal water diuresis alone. Starting from this value, an appropriate set of equations allows the separate calculation of Na reabsorption by the loop of Henle and by the distal tubule. Studies to validate this hypothesis were performed by clearance techniques during maximal water diuresis in 58 normal controls, in 19 patients with liver cirrhosis and ascites, and in 11 patients with chronic renal failure. Measurements were performed before and after the intravenous administration of 50 mg furosemide. The quantitative measurements of segmental solute reabsorption in normal subjects were consistent with results obtained by different methods in man and experimental animals, fully validating this new method. In addition, the data allowed to establish that distal reabsorption is depressed because of reduced proximal delivery in cirrhosis, as a result of impaired transport along Henle's loop in chronic renal disease, while permeability of collecting ducts to water was normal in both conditions. Though still approximate, this new furosemide test represents a considerable improvement over current methods for measuring segmental transport by the human nephron. 1983 American College of Clinical Pharmacology
AB - Abstract: A new renal function test was developed based upon the pharmacologic effects of furosemide to quantify separately the rates of electrolyte and water reabsorption by different segments of the human nephron in vivo. Since furosemide impairs active NaCl transport to Henle's loop and the attendant hypertonicity of the interstitium, osmotic water reabsorption from collecting ducts decreases and the unreabsorbed volume is lost into the urine, causing a rise in flow rate. This volume is computed from the difference in urine flow rate during furosemide with respect to that previously measured during maximal water diuresis alone. Starting from this value, an appropriate set of equations allows the separate calculation of Na reabsorption by the loop of Henle and by the distal tubule. Studies to validate this hypothesis were performed by clearance techniques during maximal water diuresis in 58 normal controls, in 19 patients with liver cirrhosis and ascites, and in 11 patients with chronic renal failure. Measurements were performed before and after the intravenous administration of 50 mg furosemide. The quantitative measurements of segmental solute reabsorption in normal subjects were consistent with results obtained by different methods in man and experimental animals, fully validating this new method. In addition, the data allowed to establish that distal reabsorption is depressed because of reduced proximal delivery in cirrhosis, as a result of impaired transport along Henle's loop in chronic renal disease, while permeability of collecting ducts to water was normal in both conditions. Though still approximate, this new furosemide test represents a considerable improvement over current methods for measuring segmental transport by the human nephron. 1983 American College of Clinical Pharmacology
UR - http://www.scopus.com/inward/record.url?scp=0020678691&partnerID=8YFLogxK
U2 - 10.1002/j.1552-4604.1983.tb02705.x
DO - 10.1002/j.1552-4604.1983.tb02705.x
M3 - Article
SN - 0091-2700
VL - 23
SP - 56
EP - 64
JO - Journal of Clinical Pharmacology
JF - Journal of Clinical Pharmacology
IS - 1
ER -