In vivo quantitation of the rat liver's ability to eliminate endotoxin from portal vein blood
The in vivo uptake of endotoxin by the liver from portal vein blood was assessed during a single passage through the liver. /sup 51/Cr labeled and unlabeled endotoxin were infused in different amounts into the femoral vein of three groups of lead-sensitized rats: a nonoperated, a sham-operated, and a surgically created reversed Eck fistula (REF) group. Whereas in the former two the infused endotoxin encounters the lung as the first filter organ, the liver performs this function in the latter experimental model. The mortality rates observed in control and sham-operated, lead-sensitized rats were found to correlate closely and reproducibly to the degree of endotoxemia. This assay was then applied to determine the amount of endotoxin eliminated by the liver by establishing, in the REF rat, the amounts of endotoxin that escaped hepatic clearance. The capacity of the liver to eliminate endotoxin from portal vein blood during a single passage increases as the portal vein endotoxin level rises; it approaches a maximum, suggesting that endotoxin's interaction with the Kupffer cells conforms to classical saturation kinetics. A Lineweaver-Burk plot prepared from these data indicates that the maximal in vivo capacity of the liver to remove endotoxin from portal vein blood approximates 1.5 micrograms/gm liver/hr. Data obtained with the use of radiolabeled endotoxin corroborate the information obtained with the bioassay technique. Endotoxin eliminated by the Kupffer cells in these quantities is slowly disintegrated; 4 hr after termination of the endotoxin infusion, less than 4% of the radiolabel is found in the urine and none in the bile. These observations indicate that the Kupffer cell's functional capacity to sequester and detoxify endotoxin is extensive and far exceeds the requirements imposed by physiological and most pathological conditions.
- Research Organization:
- Veterans Administration Medical Center, Danville, Illinois
- OSTI ID:
- 5775398
- Journal Information:
- J. Reticuloendothel. Soc.; (United States), Vol. 32:6
- Country of Publication:
- United States
- Language:
- English
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CHROMIUM 51
TRACER TECHNIQUES
DETOXIFICATION
BIOCHEMICAL REACTION KINETICS
PHAGOCYTES
BIOLOGICAL FUNCTIONS
TOXINS
EXCRETION
LABELLED COMPOUNDS
LIVER
RATS
REMOVAL
RETICULOENDOTHELIAL SYSTEM
UPTAKE
ANIMAL CELLS
ANIMAL TISSUES
ANIMALS
ANTIGENS
BETA DECAY RADIOISOTOPES
BODY
CHROMIUM ISOTOPES
CLEARANCE
DIGESTIVE SYSTEM
ELECTRON CAPTURE RADIOISOTOPES
EVEN-ODD NUCLEI
FUNCTIONS
GLANDS
INTERMEDIATE MASS NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MAMMALS
MATERIALS
NUCLEI
ORGANS
RADIOISOTOPES
REACTION KINETICS
RODENTS
SOMATIC CELLS
TISSUES
TOXIC MATERIALS
VERTEBRATES
551001* - Physiological Systems- Tracer Techniques