Endocytosis of heat-denatured albumin by cultured rat Kupffer cells
Purified Kupffer cells were obtained by centrifugal elutriation of sinusoidal cells isolated by pronase treatment of the rat liver. The endocytosis of radioactively labeled heat-aggregated colloidal albumin (CA /sup 125/I) was investigated in maintenance cultures of the purified Kupffer cells. The endocytic capacity of the cells was studied during 4 days of culture. Maximum uptake was observed after 24 hr of culture, with a gradual decline during the following days. When the uptake was measured after incubation with increasing concentrations of CA /sup 125/I, a saturation effect was observed. This finding and the observed high rate of uptake are strong indications that receptor sites on the cell membrane are involved in the mechanism of endocytosis. The uptake of CA /sup 125/I by Kupffer cells was inhibited by the metabolic inhibitors fluoride and antimycin A, indicating that endocytosis of CA /sup 125/I is dependent on energy derived from both glycolysis and mitochondrial respiration. The mechanism of internalization may also require the action of microfilaments as well as intact microtubules, since both cytochalasin B and colchicine inhibited the uptake of CA /sup 125/I. The intracellular degradation of CA /sup 125/I by Kupffer cells was strongly inhibited by chloroquine but not by colchicine. The degradation of ingested CA /sup 125/I occurred within the Kupffer cell lysosomes.
- Research Organization:
- Institute for Experimental Gerontology TNO, Rijswijk, The Netherlands
- OSTI ID:
- 5748818
- Journal Information:
- J. Reticuloendothel. Soc.; (United States), Journal Name: J. Reticuloendothel. Soc.; (United States) Vol. 32:4; ISSN JRSOD
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
ALBUMINS
ANIMAL CELLS
ANIMAL TISSUES
BETA DECAY RADIOISOTOPES
BODY
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
IN VITRO
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PHAGOCYTES
PHAGOCYTOSIS
PROTEINS
RADIOISOTOPES
RETICULOENDOTHELIAL SYSTEM
SOMATIC CELLS
TISSUES
TRACER TECHNIQUES
UPTAKE