## Abstract Theophylline, a cyclic nucleotide phosphodiesterase inhibitor, increases the rate of tyrosine aminotransferase (TAT) degradation in rat hepatoma tissue culture (HTC) cells. Theophylline (0.1โ10 mM) causes a twoโ to fiveโfold increase in intracellular cAMP concentration but a 30โ60% decr
The influence of culture conditions on the induction of tyrosine aminotransferase by cyclic nucleotides in rat hepatoma cells
โ Scribed by Robert H. Stellwagen; Kulwant K. Kohli; Rochelle D. Sailor
- Publisher
- John Wiley and Sons
- Year
- 1977
- Tongue
- English
- Weight
- 761 KB
- Volume
- 91
- Category
- Article
- ISSN
- 0021-9541
No coin nor oath required. For personal study only.
โฆ Synopsis
Abstract
The increase in tyrosine aminotransferase activity which occurs in rat hepatoma tissue culture (HTC) cells in response to cyclic AMP analogs has been shown to be an enzyme induction, similar to the larger response observed in certain other hepatoma cells and in liver. A specific antibody to tyrosine aminotransferase has been used to show that the number of enzyme molecules and the rate of enzyme synthesis are increased by N^6^,O^2โฒ^โdibutyryl cyclic AMP in HTC cells. The effect on tyrosine aminotransferase is also produced by various 8โsubstituted derivatives of cyclic AMP and occurs whether or not the enzyme has been preinduced with a glucocorticoid. The response of the enzyme is greater when HTC cells are maintained in monolayer than in suspension cultures. Neither cell growth nor serum is required for the response.
๐ SIMILAR VOLUMES
## Abstract The role of the nucleus in bringing about the induction of tyrosine aminotransferase (TAT) by glucocorticosteroid hormone and its deinduction upon steroid removal has been studied in enucleated rat hepatoma tissue culture cells (FU5โ5). Both processes require the presence of the nucleus
## Abstract The effects of actinomycinโD and 3โฒโdeoxyadenosine (cordycepin) on the steroidโmediated induction of tyrosine aminotransferase (TAT) synthesis have been reexamined in view of recent reports that the primary inhibitory action of these compounds may affect synthesis of proteins as well as
We investigated the relationship between the expression of tyrosine aminotransferase (TAT) and cytoskeletal systems of cultured rat hepatocytes by using serumfree culture conditions and changing three factors: 1) the concentration of calcium, 2) the dish-coating material, and 3) the cell-plating den
Sodium butyrate acts as a differentiation-promoting agent for a wide variety of cell types, including some tumor cell lines. In this study, we examined the effects of sodium butyrate (SB) on the functional differentiation of cultured WB-F344 rat liver epithelial stemlike cells. Treatment of WB-F344