Modulation by dexamethasone of the fatty acyl-CoA desaturase system in Tetrahymena microsomes.
Dexamethasone produced an increased activity of stearoyl-CoA desaturase through the enhancement of delta 9-terminal component activity, and a corresponding decrease of oleoyl-CoA desaturase activity via the reduced activity of delta 12-terminal component in Tetrahymena microsomes. However, the content of cytochrome b5 as well as the activities of NAD(P)H-cytochrome c and NADH-ferricyanide reductases showed no significant changes by dexamethasone. Additionally, dexamethasone evoked a 3.5-fold increase of intracellular cyclic AMP content 2 hr after administration. These results suggest that dexamethasone may modulate microsomal fatty acyl-CoA desaturase system in Tetrahymena by increasing intracellular cyclic AMP content.
D000818:Animals; D000242:Cyclic AMP / Q000096:biosynthesis; D003907:Dexamethasone / Q000494:pharmacology*; D004579:Electron Transport / Q000187:drug effects; D044943:Fatty Acid Desaturases / Q000378:metabolism*; D007700:Kinetics; D008861:Microsomes / Q000187:drug effects / Q000201:enzymology*; D013230:Stearoyl-CoA Desaturase / Q000378:metabolism; D013769:Tetrahymena pyriformis / Q000648:ultrastructure*
D003907:Dexamethasone; D000242:Cyclic AMP; D044943:Fatty Acid Desaturases; D013230:Stearoyl-CoA Desaturase