Effect of insulin-treatment on age-dependent decrease of lipogenic enzyme induction.
The effects of insulin-treatment on induction of liver lipogenic enzymes by a fat-free diet were investigated in 1-, 2- and 9-month-old rats. The magnitudes of the induction of the enzymes were very high in 1-month-old rats and decreased with aging (Iritani, N., Fukuda, H. and Fukuda, E. (1981) Biochim. Biophys. Acta 665, 636). The induction of lipogenic enzymes was not affected by insulin injection in young rats. In 9-month-old rats, however, although the maximal magnitudes of the induction were not affected by the insulin injection, the lag periods of the induction were shortened. The lipogenic enzyme induction in 9-month-olds did not correlate with plasma insulin level but paralleled changes in the insulin binding capacities to liver plasma membranes and adipocytes. The results suggest that insulin binding is implicated in age-dependent decrease of lipogenic enzyme induction, and support our previous report (Iritani, N., Fukuda, H., Tashiro, S. and Ikeda, Y. (1982) J. Biochem. 92, 569).
D000103:Acetyl-CoA Carboxylase / Q000378:metabolism*; D000273:Adipose Tissue / Q000378:metabolism*; D000375:Aging; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D004790:Enzyme Induction; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism*; D007328:Insulin / Q000494:pharmacology*; D008025:Ligases / Q000378:metabolism*; D008099:Liver / Q000201:enzymology / Q000254:growth & development*; D008291:Malate Dehydrogenase / Q000378:metabolism*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011972:Receptor, Insulin / Q000378:metabolism
D001786:Blood Glucose; D007328:Insulin; D008291:Malate Dehydrogenase; C031917:malate dehydrogenase (oxaloacetate-decarboxylating) (NADP+); D005954:Glucosephosphate Dehydrogenase; D011972:Receptor, Insulin; D008025:Ligases; D000103:Acetyl-CoA Carboxylase