Isoenzymes of pyruvate kinase, lactate dehydrogenase and alkaline phosphatase in epithelial cell lines of rat liver.

In cultured epithelial cells of rat liver the isoenzyme patterns of pyruvate kinase, lactate dehydrogenase and alkaline phosphatase were studied and compared with those of freshly isolated parenchymal and non-parenchymal liver cells. In all epithelial cell lines pyruvate kinase was not activated by fructose 1,6-bisphosphate, suggesting the absence of the L-isoenzyme. Cell lines derived from livers of newborn rats expressed LDH-4 and -5, whereas cell lines developed from fetal rat livers contained all 5 lactate dehydrogenase isoenzymes. In the latter case the pattern was found to depend on the state of confluence. All cell lines exhibited only a single alkaline phosphatase form, however, differences were found with respect to electrophoretic mobility.