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Distribution of hexokinase and glucokinase between parenchymal and non‐parenchymal cells of rat liver
Author(s) -
Sapag-Hagar M.,
Marco R.,
Sols A.
Publication year - 1969
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(69)80099-2
Subject(s) - glucokinase , parenchyma , hexokinase , distribution (mathematics) , chemistry , biochemistry , glycolysis , biology , pathology , enzyme , medicine , mathematical analysis , mathematics
Phosphorylation is the first catalyzed step in glucose utilization by liver. The discovery in rat liver of a special isoenzyme for this reaction, the insulin dependent, high Km glucokinase by Vifiuela, Salas and Sols [I] , opened the way for a significant increase in the understanding of the regulation of glucose metabolism in liver. Nevertheless, the additional presence of constitutive, low Km hexokinase in rat liver was somewhat disturbing. Sols and coworkers [2,3] advanced the idea that the glucokinase, being an enzyme apparently unique to the liver, would be restricted to the parenchymal cells of this organ, while the common hexokinase found in homogenates could be contributed, at least mainly, by the mesenchymatous tissue. In order to test experimentally this hypothesis we have undertaken the isolation of parenchymal and non-parenchymal fractions from rat liver. The results indicate that indeed these two enzymes have essentially different cellular location in liver, the hepatocytes being virtually free of hexokinase.