Endotoxin inhibition of glucocorticoid enzyme induction and in vivo 3H-dexamethasone labelling of rat liver nuclei.
1. The effect of endotoxin on glucocorticoid (GC) induction of liver TO and TAT was investigated. 2. It was found that endotoxin inhibited not only TO GC induction, but also that of TAT, though to a lesser extent (17.41%). 3. Endotoxin did not influence the binding capacity of liver cytosol for 3H-dexamethasone at the second hour after the toxin administration. 4. In in vivo experiments endotoxin inhibited with 57.2% the binding of 3H-dexamethasone to hepatic nuclei. 5. It is suggested that the lower extent of endotoxin inhibition of GC induction of TAT may be due to the counteracting action of some inductor(s) for TAT only.
Vaptzarova
K I
KI
Regeneration Research Laboratory, Bulgarian Academy of Sciences, Sofia.
Baramova
E N
EN
Popov
P G
PG
D000315:Adrenalectomy; D000818:Animals; D001667:Binding, Competitive; D002467:Cell Nucleus / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D003907:Dexamethasone / Q000378:metabolism*; D004731:Endotoxins / Q000494:pharmacology*; D004790:Enzyme Induction / Q000187:drug effects; D005938:Glucocorticoids / Q000494:pharmacology*; D008099:Liver / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D014366:Tryptophan Oxygenase / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D014444:Tyrosine Transaminase / Q000037:antagonists & inhibitors* / Q000096:biosynthesis
D004731:Endotoxins; D005938:Glucocorticoids; D003907:Dexamethasone; D014366:Tryptophan Oxygenase; D014444:Tyrosine Transaminase