Initial plasma disappearance and tissue uptake of 131I-albumin in normal rabbits

Journal Article · Wed May 01 00:00:00 EDT 1991 · Microvascular Research; (United States)

DOI:https://doi.org/10.1016/0026-2862(91)90033-8· OSTI ID:5450748

Bent-Hansen, L ^[1]

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1. Department of Medicine B, Rigshospitalet, University of Copenhagen (Denmark)

The simultaneous plasma disappearance curves of 131I-albumin and 125I-fibrinogen were recorded in normal rabbits for 1 hr. Using fibrinogen as a plasma reference, the disappearance curves of albumin were shown to contain two separate phases of efflux: one fast from zero to 10 min. comprising 8% of the total tracer; and one slow appearing in the interval of 10 to 60 min. containing another 9% of the tracer. Total albumin escape was analyzed to yield an initial slope of 0.024 {plus minus} 0.004 min-1, corresponding to a wholebody unidirectional albumin clearance (Cl(0)) of 0.090 {plus minus} 0.009 ml(min{asterisk}100 g)-1. The distribution of efflux was assessed by biopsy uptakes using the same tracers in spleen, kidney, heart, lung, liver, intestine, skin, muscle, and brain. The disappearance curve generally reflects a biphasic pattern of uptake in peripheral tissue, predominantly by muscle and lung. The rapid phase has contributions from the fast near equilibration of liver, and intestine and skin are significant codeterminants of the slow phase. Due to their low body masses highly perfused organs such as kidney, spleen, and heart have little influence on the plasma disappearance. In accordance, the Cl(0) determined for the wholebody was higher than initial clearances found in skin (0.053 ml(min{asterisk}100 g)-1) and muscle (0.054 ml(min{asterisk}100 g)-1), but much lower than those found in the highly perfused organs. The initial (unidirectional) rates of peripheral albumin transfer demonstrated, ranged from 10 to 30 times higher than estimates of lymphatic return, suggesting that transcapillary albumin exchange is mediated by high-rate bidirectional diffusion. The rapid decrease of net albumin exchange rates suggests a second, highly significant barrier located within the interstitial matrix, which restricts plasma escape and reduces plasma to lymph albumin transport.

• OSTI ID: 5450748
• Journal Information: Microvascular Research; (United States), Vol. 41:3; ISSN 0026-2862
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ALBUMINS
BLOOD-PLASMA CLEARANCE
FIBRINOGEN
IODINE 125
IODINE 131
METABOLISM
RABBITS
TISSUE DISTRIBUTION
TRACER TECHNIQUES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BLOOD COAGULATION FACTORS
CLEARANCE
COAGULANTS
DAYS LIVING RADIOISOTOPES
DISTRIBUTION
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
GLOBULINS
HEMATOLOGIC AGENTS
HEMOSTATICS
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
MAMMALS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PROTEINS
RADIOISOTOPES
VERTEBRATES
550501* - Metabolism- Tracer Techniques