[The role of disorders in the tubular transport of water and osmotically active substances in the progression of chronic kidney failure].
Lithium clearance served the criterion for measuring proximal and distal tubular transport of water, sodium and osmotically active substances (OAS) in 41 patients with chronic renal failure (CRF) of various degree. Distal reabsorption of water and sodium occurs early in CRF. In moderate disease the authors observed a drastic rise in distal excreted fraction of OAS which surpassed that of sodium threefold. Proximal fractional excretion of water acquired defects in advanced CRF only. In the range of creatinine clearance 30-65 ml/min an inverse relationship appeared between the clearance and the ratio of urea of OAS concentrations to chlorine concentrations. Distal fractional OAS excretion correlated with relevant parameters directly. It is suggested that a decline in relative chlorine ions content in the tubular fluid at the site of the thick spot entails hypoactivity of the tubular-glomerular feedback mechanisms resultant in hypertension and hyperfiltration in the intact nephrons which start to perish because of overloading.
A M
AM
Esaian
I G
IG
Kaiukov
D000328:Adult; D001692:Biological Transport; D003404:Creatinine / Q000032:analysis / Q000378:metabolism; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000378:metabolism*; D007684:Kidney Tubules / Q000378:metabolism*; D008094:Lithium / Q000032:analysis / Q000378:metabolism; D008297:Male; D009995:Osmosis; D014867:Water / Q000378:metabolism*
D014867:Water; D008094:Lithium; D003404:Creatinine