Postglomerular capillary solute flux restricted by shape and charge in the dog

Journal Article · Tue Sep 01 00:00:00 EDT 1987 · American Journal of Physiology; (USA)

OSTI ID:5052880

Whiteside, C; Silverman, M ^[1]

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1. Univ. of Toronto, Ontario (Canada)

The permselectivity characteristics of the postglomerular (PG) microcirculation in dog kidney were investigated employing {sup 3}H-labeled cationic (DEAE) and anionic sulfated dextrans (dextran-SO{sub 4}) ranging from 19 to 29 {angstrom} Stokes-Einstein Radius. With the use of the multiple-indicator dilution (MID) technique, a bolus injection was made into the left renal artery and timed serial samples were obtained from renal venous and urine outflows. The injection solution contained {sup 125}I-labeled albumin (plasma reference), ({sup 14}C)inulin and/or creatinine (glomerular and interstitial references), and a test ({sup 3}H)dextran probe. A control run was carried out with tracer, then charge interaction was analyzed by repeating the MID run with excess unlabeled compound or after protamine sulfate infusion. After loading, renal vein recovery and mean transit time ({bar t}) were unchanged relative to ({sup 14}C)inulin for ({sup 3}H)dextran-SO{sub 4}. But excess DEAE resulted in reduced recovery and decreased {bar t} for ({sup 3}H)DEAE. After protamine sulfate, the renal vein and urine recoveries of ({sup 3}H)dextran-SO{sub 4} decreased and the renal vein {bar t} increased. These findings demonstrate saturable anionic binding sites in the PG microcirculation. Under conditions where charge interaction was eliminated, the ratio of renal vein {bar t} for {sup 125}I-albumin to cationic or anionic dextran was always less than its ratio to neutral dextran, implying a larger apparent volume of distribution. The authors concluded that PG capillaries also limit solute flux on the basis of shape.

• OSTI ID: 5052880
• Journal Information: American Journal of Physiology; (USA), Vol. 253:3; ISSN 0002-9513
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
DEXTRAN
MEMBRANE TRANSPORT
GLOMERULI
BLOOD FLOW
TRITIUM COMPOUNDS
CAPILLARIES
CARBON 14 COMPOUNDS
DOGS
INULIN
KIDNEYS
SHAPE
SULFATES
VEINS
ANIMALS
BLOOD SUBSTITUTES
BLOOD VESSELS
BODY
CARBOHYDRATES
CARDIOVASCULAR SYSTEM
DRUGS
HEMATOLOGIC AGENTS
HYDROGEN COMPOUNDS
LABELLED COMPOUNDS
MAMMALS
ORGANIC COMPOUNDS
ORGANS
OXYGEN COMPOUNDS
POLYSACCHARIDES
SACCHARIDES
SULFUR COMPOUNDS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques