NUTRITIONAL REGULATION OF LIPOGENIC ENZYME GENE-EXPRESSION IN RAT EPIDIDYMAL ADIPOSE-TISSUE

The time courses of gene expression, and the nutritional regulation of gene expression of lipogenic enzymes (acetlyl-CoA carboxylase, fatty acid synthase, ATP citrate-lyase, malic enzyme, and glucose-6-phosphat e dehydrogenase) in epididymal adipose tissue after refeeding food-dep rived rats have been investigated and compared with those in liver (pr eviously reported), The mRNA concentrations of lipogenic enzymes reach ed maximum levels at 24 h after the refeeding in adipose tissue and at 8-16 h in liver, while the enzyme induction reached maximum at 48-72 h in both tissues. Moreover, the mRNAs were more strongly induced in a dipose tissue than in liver, whereas the enzyme induction (except mali c enzyme) was lower, In adipose tissue of rats fed a carbohydrate diet without protein, the mRNA concentrations of acetyl-CoA carboxylase, A TP-citrate lyase, malic enzyme, and fatty acid synthase reached compar able levels to those of the carbohydrate/protein diet group. The prote in feeding increased the enzyme induction in adipose tissue. As regard s reduction of gene expression, lipogenic enzyme mRNA concentrations w ere not so markedly reduced by starvation or polyunsaturated fatty aci ds in adipose tissue as in liver, The differences in regulation of lip ogenic enzyme gene expression and induction between adipose tissue and liver can be ascribed to tissue specificity.