The action of insulin and dibutyryl cyclic AMP on the biosynthesis of polyunsaturated acids ofα-linolenic acid family in HTC cells

1976 ◽  
Vol 12 (1) ◽  
pp. 3-8 ◽  
Author(s):  
María J. T. de Alaniz ◽  
I. Nelva T. de Gómez Dumm ◽  
Rodolfo R. Brenner
Keyword(s):  
Cyclic Amp ◽  
Linolenic Acid ◽  
Dibutyryl Cyclic Amp ◽  
Polyunsaturated Acids ◽  
Htc Cells

scholarly journals REGULATION OF PHOSPHOENOLPYRUVATE CARBOXYKINASE AND TYROSINE TRANSAMINASE IN HEPATOMA CELL CULTURES

1974 ◽  
Vol 60 (1) ◽  
pp. 181-191 ◽  
Author(s):  
Han van Rijn ◽  
Marinus M. Bevers ◽  
Roeland van Wijk ◽  
Wesley D. Wicks
Keyword(s):  
Growth Rate ◽  
Cyclic Amp ◽  
Dna Synthesis ◽  
Cell Cultures ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Hepatoma Cell ◽  
Transaminase Activity ◽  
Dibutyryl Cyclic Amp ◽  
Tyrosine Transaminase ◽  
Htc Cells

The ability of N6, O2'-dibutyryl cyclic AMP (DBcAMP) to regulate a number of metabolic events in four lines of cultured rat hepatomas has been examined. Although dexamethasone induces tyrosine transaminase in all four lines, DBcAMP induces this enzyme normally only in H35 cells. A slight increase in transaminase activity was seen with MH1C1 cells and HTC cells, but no effect was detectable in RLC cells. In contrast, phosphoenolpyruvate carboxykinase activity is increased by both agents in H35 and MH1C1 cells, but neither had any effect in HTC or RLC cells. DBcAMP caused a rapid inhibition of the growth rate and DNA synthesis and an increase in protein content in both H35 and MH1C1 cells but not in HTC or RLC cells. The effect of DBcAMP on DNA synthesis in MH1C1 cells could be reversed by deoxycytidine as is also the case with H35 cells. The resistance of HTC and RLC cells to DBcAMP was not due to reduced uptake or deacylation as judged by studies with [3H]DBcAMP. The cyclic nucleotide appears to enter the cells by passive diffusion as the intracellular concentration approaches that in the medium within 30–60 min. Possible explanations for the differential responses observed are discussed.

The inhibitory effects of some adenosine nucleolipids on the lipolysis in rat epididymal fat pads in vitro

1979 ◽  
Vol 44 (5) ◽  
pp. 1651-1656 ◽  
Author(s):  
Sixtus Hynie ◽  
Jiří Smrt
Keyword(s):  
Fatty Acids ◽  
Cyclic Amp ◽  
Dibutyryl Cyclic Amp ◽  
Inhibitory Effects ◽  
Epididymal Fat ◽  
Fat Pads

3'-Oleolyl-2,3-dihydroxypropyl-AMP, 3'-stearoyl-2,3-dihydroxypropyl-AMP, octadecyl-AMP and palmitamidoethyl-AMP inhibited in comparison with adenosine or fatty acids much stronger the lipolysis in rat epididymal fat pads in vitro stimulated by isoproterenol, theophylline and dibutyryl cyclic AMP. The inhibition of the effects of the two latter drugs suggest that the described effect is caused not only by the inhibition of the cyclic AMP production but also by the inhibition of its effect on the following steps in process of lipolysis.

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