title: cAMP analogues inhibit phosphatidylcholine biosynthesis in cultured rat hepatocytes.
abstract: The effect of cAMP analogues on phosphatidylcholine formation via the CDP-choline pathway was investigated in cultured monolayers of rat hepatocytes. Treatment with chlorophenylthio-cAMP or the cAMP phosphodiesterase inhibitor, aminophylline, reduced the total uptake of [methyl-3H]choline by 32 and 26% (p less than 0.01), respectively. Chlorophenylthio-cAMP inhibited the incorporation of [methyl-3H]choline into phosphatidylcholine by 2.5-fold (p less than 0.001) and reduced the rate of phosphatidylcholine biosynthesis by approximately 40%. Aminophylline, 8-bromoadenosine 3':5'-monophosphate and N6,O2'-dibutyryladenosine 3':5'-monophosphate also inhibited [methyl-3H]choline incorporation into phosphatidylcholine. Although choline kinase and phosphocholinetransferase activities were stimulated by chlorophenylthio-cAMP treatment, CTP: phosphocholine cytidylyltransferase activity was reduced 46% (p less than 0.01). The results indicate that cytidylyltransferase may be phosphorylated and inhibited by cAMP-dependent protein kinases.
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D015124:8-Bromo Cyclic Adenosine Monophosphate; D000628:Aminophylline / Q000494:pharmacology; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000031:analogs & derivatives* / Q000494:pharmacology; D005260:Female; D007700:Kinetics; D008099:Liver / Q000187:drug effects* / Q000378:metabolism*; D010713:Phosphatidylcholines / Q000096:biosynthesis*; D051381:Rats
chemical_list: D010713:Phosphatidylcholines; D015124:8-Bromo Cyclic Adenosine Monophosphate; D000628:Aminophylline; D003994:Bucladesine; D000242:Cyclic AMP; D015056:1-Methyl-3-isobutylxanthine