Urinary loss of glucose, phosphate, and protein by diffusion into proximal straight tubules injured by D-serine and maleic acid

Journal Article · Sat Jun 01 04:00:00 EDT 1985 · Lab. Invest.; (United States)

OSTI ID:5149368

Carone, F A; Nakamura, S; Goldman, B

In several models of acute renal failure leakage of glomerular filtrate out of the tubule is an important pathogenetic mechanism; however, bidirectional diffusion of solute to account for certain pathophysiologic features of acute renal failure has received meager attention. Using micropuncture and clearance methods, the authors assessed sequentially leakage of solutes and inulin across proximal straight tubules (PST) injured by two nephrotoxins. In d-serine-treated rats with extensive necrosis of PST, the basis for glucosuria and tubular leakage of inulin was studied. Glucose absorption by the proximal convoluted tubule and glucose delivery to the PST were normal, but glucose delivery to the distal tubule was increased nearly 8-fold, indicating diffusion of glucose from interstitial to tubular luminal fluid across the necrotic PST. Total kidney inulin clearance was greatly reduced, but single nephron glomerular filtration rate, based on proximal convoluted tubule samples, was normal, indicating tubular loss of inulin. Urinary recovery of (/sup 14/C)inulin infused into tubular lumina revealed that proximal convoluted tubule and distal tubule were impermeable to inulin and that inulin diffused out of the necrotic PST. The progressive return over 6 days of tubular impermeability for inulin correlated with relining of PST with new cells. In maleic acid-treated rats the site and extent of tubular necrosis and the nature of urinary loss of solutes were studied. Microdissection revealed that maleic acid caused limited necrosis of PST which averaged 7.4% of total proximal tubular length. Increased urinary excretion of protein, phosphate, and glucose and increased tubular permeability to microinfused (/sup 14/C)inulin occurred with the onset of PST necrosis, and return of these abnormalities to normal correlated with the degree of cellular repair of the PST.

• Research Organization: Northwestern Univ. Medical School, Chicago, IL
• OSTI ID: 5149368
• Journal Information: Lab. Invest.; (United States), Journal Name: Lab. Invest.; (United States) Vol. 6; ISSN LAINA
• Country of Publication: United States
• Language: English

Related Subjects

550901* -- Pathology-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALDEHYDES
AMINO ACIDS
ANIMALS
BIOLOGICAL RECOVERY
BODY
CARBOHYDRATES
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
CLEARANCE
DICARBOXYLIC ACIDS
DIFFUSION
DISEASES
EXCRETION
GLUCOSE
GLYCOSURIA
HEXOSES
HYDROXY ACIDS
INULIN
ISOTOPE APPLICATIONS
KIDNEYS
LABELLED COMPOUNDS
MALEIC ACID
MAMMALS
METABOLIC DISEASES
MONOSACCHARIDES
NECROSIS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
OXYGEN COMPOUNDS
PATHOLOGICAL CHANGES
PERMEABILITY
PHOSPHATES
PHOSPHORUS COMPOUNDS
POLYSACCHARIDES
PROTEINS
RATS
RECOVERY
RENAL CLEARANCE
RODENTS
SACCHARIDES
SERINE
TOXICITY
TRACER TECHNIQUES
UROGENITAL SYSTEM DISEASES
VERTEBRATES