Regulation of rat alcohol dehydrogenase by cyclic AMP in primary hepatocyte culture.
Alcohol dehydrogenase (ADH) is enhanced separately by epinephrine and by glucagon in primary rat hepatocyte culture. This study determined whether cyclic AMP, a common mediator for some of the actions of the above hormones, increases ADH. Administration of theophylline, a cyclic AMP phosphodiesterase inhibitor which increases endogenous cyclic AMP, in a dose of 100 mg/kg to rats for 5 days, increased ADH activity. Dibutyryl cyclic AMP (10 microM) added to primary hepatocytes in culture increased ADH mRNA and ADH activity at 12 and 24 h, respectively, after its addition. The increase in ADH mRNA was preceded by an increase in the expression of C/EBP beta mRNA and in C/EBP beta protein. Dibutyryl cyclic AMP, in transient transfection experiments of primary rat hepatocyte culture, activated an ADH promoter gene construct containing the C/EBP binding site, but failed to activate a construct containing a 4-bp mutation at this site. These results show that cyclic AMP induces ADH and suggests that this effect is mediated by C/EBP beta binding to the C/EBP site. The previously demonstrated induction of ADH by epinephrine and glucagon may be mediated by a common pathway via an increase in cyclic AMP.
Potter
J J
JJ
Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
MacDougald
O A
OA
Mezey
E
E
D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000037:antagonists & inhibitors; D000426:Alcohol Dehydrogenase / Q000096:biosynthesis*; D000704:Analysis of Variance; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology*; D022762:CCAAT-Enhancer-Binding Proteins; D002478:Cells, Cultured; D015500:Chloramphenicol O-Acetyltransferase / Q000096:biosynthesis; D000242:Cyclic AMP / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000096:biosynthesis; D004789:Enzyme Activation; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects / Q000502:physiology*; D007700:Kinetics; D007770:L-Lactate Dehydrogenase; D008099:Liver / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D009687:Nuclear Proteins / Q000096:biosynthesis; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000096:biosynthesis; D013806:Theophylline / Q000494:pharmacology; D013997:Time Factors; D014157:Transcription Factors / Q000096:biosynthesis; D014158:Transcription, Genetic / Q000187:drug effects; D014162:Transfection
D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D014157:Transcription Factors; D003994:Bucladesine; D013806:Theophylline; D000242:Cyclic AMP; D000426:Alcohol Dehydrogenase; D007770:L-Lactate Dehydrogenase; D015500:Chloramphenicol O-Acetyltransferase; D015105:3',5'-Cyclic-AMP Phosphodiesterases