Study of some enzymatic activities in human liver cell cultures

Some enzymatic activities were studied in long ter cultures of human liver cells : glucose-6-phosphatase, U.D.P. glucuronosyltransferase, phenylalanine 4-hydroxylase and tyrosine aminotransferase. Only weak tyrosine aminotransferase activity has been found in 12 subcultures, and it has not been increased by addition of corticoids. This tyrosine aminotransferase activity has been measured at different passages of the culture. Our results are compared with those found in literature. The different reasons which could explain the absence of liver specific biochemical functions have been discussed.