The growth hormone-dependent decrease in hepatic fatty acid synthase mRNA is the result of a decrease in gene transcription.
The present study was conducted to determine the chronic effects of porcine growth hormone administration on fatty acid synthase (FAS) mRNA abundance and gene transcription in growing rats. Growth hormone treatment increased growth rate approximately 27% (P<0.01). Porcine growth hormone decreased FAS mRNA levels by 55%. The reduction in FAS mRNA was due to a marked decrease in transcription of the FAS gene (decreased by 80%). In contrast, porcine growth hormone did not affect mRNA abundance or transcription rate of another insulin-regulated gene, phosphoenolpyruvate carboxykinase. In summary, our results have established that chronic treatment with growth hormone decreases FAS mRNA by decreasing the transcription rate of the gene. Furthermore, they suggest that the effects of growth hormone are specific and are not mediated by general changes in insulin-responsive gene expression in liver.
Donkin
S S
SS
Department of Dairy and Animal Science, The Pennsylvania State University, University Park 16802, USA.
McNall
A D
AD
Swencki
B S
BS
Peters
J L
JL
Etherton
T D
TD
D000818:Animals; D001483:Base Sequence; D004247:DNA / Q000235:genetics; D064429:Fatty Acid Synthases / Q000235:genetics*; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D013006:Growth Hormone / Q000494:pharmacology*; D066298:In Vitro Techniques; D007328:Insulin / Q000494:pharmacology; D008099:Liver / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D008969:Molecular Sequence Data; D010729:Phosphoenolpyruvate Carboxykinase (GTP) / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013552:Swine; D014158:Transcription, Genetic / Q000187:drug effects
D007328:Insulin; D012333:RNA, Messenger; D013006:Growth Hormone; D004247:DNA; D064429:Fatty Acid Synthases; D010729:Phosphoenolpyruvate Carboxykinase (GTP)