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Cellular heterogeneity in binding and uptake of low‐density lipoprotein in primary rat hepatocytes
Author(s) -
Corsetti James P.,
Sparks Janet D.,
Sikora Barbara,
Sparks Charles E.
Publication year - 1993
Publication title -
hepatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.488
H-Index - 361
eISSN - 1527-3350
pISSN - 0270-9139
DOI - 10.1002/hep.1840170419
Subject(s) - lipoprotein , catabolism , dissociation constant , low density lipoprotein , hepatocyte , population , propidium iodide , flow cytometry , chemistry , biochemistry , high density lipoprotein , biology , medicine , endocrinology , metabolism , biophysics , cholesterol , microbiology and biotechnology , in vitro , apoptosis , receptor , programmed cell death , environmental health
Abstract Hepatocellular heterogeneity of biochemical function is well established for many aspects of liver metabolism. This study addresses the question of cellular heterogeneity in the catabolism of low‐density lipoprotein by rat hepatocytes. Low‐density lipo‐protein binding (4° C) and uptake (37° C) by rat hepatocytes were studied by use of human low‐density lipoprotein labeled with a highly fluorescent lipophilic probe, N, N‐dipentadecylaminostyrylpyridinium iodide, recently developed by us. Single‐cell suspensions derived from rat hepatocytes in primary culture and from liver perfusion were studied with flow cytometry with and an approximation algorithm for data analysis. These studies show subpopulations of cells negative and positive for the specific binding and uptake of low‐density lipoprotein. Dissociation constants for low‐density lipoprotein binding and uptake were determined for the total population (18 μg/ml, binding; 12 μg/ml, uptake) and found to be in good agreement with previously reported values. Additionally, the dissociation constant for binding for the positive subpopulation was determined and found to be 3 μg/ml. This lower value is more typical of the values seen in other cell types. These findings are strongly suggestive of functional heterogeneity in the hepatic catabolism of low‐density lipoprotein. (H EPATOLOGY 1993;17:645–650.)