Induction of γ-Glutamyl Transferase by Dexamethasone in Cultured Fetal Rat Hepatocytes

Abstract

Hepatocytes isolated as a relatively pure population from normal fetal rats were maintained in primary monolayer culture for 4-10 days. Hepatocytes exhibited a small increase in basal γ-glutamyl transferase (GGT) activity over time. Exposure to dexamethasone (10^-6 mol/l) elicited a rise in GGT activity after a lag of 24 h. The presence of the steroid was necessary to maintain induction, and its removal resulted in reversal of induction. The maximal response was 2- to 3-fold, 72 h after exposure to the steroid. After this maximal response, a gradual decay in enzyme activity occurred, despite the continuous presence of the hormone. Actinomycin D or cycloheximide given prior to/or simultaneously with the steroid prevented the induction, thus suggesting that both RNA and protein biosynthesis are necessary for induction to occur.

Change in Localization of Alkaline Phosphatase and Mannosidase II by Colchicine Treatment of Primary Cultures of Fetal Rat Hepatocytes

“…Livers were removed from fetal rats at gestation day 17 under aseptic conditions. We dissociated the livers by modifying the method of Cotariu et al [ 15 ]. Livers were cut into small pieces, which were then incubated with stirring for 10 min at 37°C in 0.05% collagenase (Type II: Worthington Biochemical Co., Freehold, NJ, USA) dissolved in Hanks’ balanced salt solution containing 0.5% serum albumin.…”

Localization of alkaline phosphatase and proteins related to intercellular junctions in primary cultures of fetal rat hepatocytes

“…Livers were excised from fetal rats, and cut into small pieces. Dissociation of livers was performed by modifying the method of Cotariu et al (1988). Small pieces of liver were stirred for 10 min at 37°C in 0.05% collagenase (TypeII: Worthington Biochemical Co., Freehold, New Jersey, USA) dissolved in Hanks' balanced salt solution containing 0.5% serum albumin.…”