[Influence of thyroid status on microsomal and peroxysomal enzyme induction by fibrates in rats].
The influence of thyroid hormones upon the inductive effects on microsomal enzymes and the hepatic proliferation produced by different fibrates was studied in the male rat. A pharmacological dose of triiodo-L-thyronine significantly lowers the total cytochrome P450 content induced by some equi-effective doses of clofibrate, ciprofibrate, bezafibrate and fenofibrate. The ethoxycoumarin O-deethylase activity (ECOD) is concomitantly decreased. On the contrary, L-T3 accentuates the specific inductive effect of fibrates on bilirubin-UDPGT activity. Hypothyroid has little or no influence upon the effect of fibrates towards cytochrome P450 content and ECOD activity. On the other hand, this thyroid status significantly lowers the CN- palmitoyl coenzyme A dehydrogenase, which is a marker enzyme of the peroxisome proliferation caused by the different fibrates. These results indicate a possible modulation of thyroid hormones within the fibrates induction mechanism in the rat.
Charmoillaux
M
M
Formation de Biochimie pharmacologique, UFR Pharmacie, Dijon.
Goudonnet
H
H
Mounié
J
J
Magdalou
J
J
Escousse
A
A
Truchot
R C
RC
D042964:Acyl-CoA Dehydrogenase; D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D044943:Fatty Acid Desaturases / Q000378:metabolism; D014453:Glucuronosyltransferase / Q000378:metabolism; D005993:Glycerolphosphate Dehydrogenase / Q000378:metabolism; D000960:Hypolipidemic Agents / Q000494:pharmacology*; D008099:Liver / Q000648:ultrastructure; D008297:Male; D008830:Microbodies / Q000201:enzymology*; D008862:Microsomes, Liver / Q000201:enzymology*; D051381:Rats; D011919:Rats, Inbred Strains; D013963:Thyroid Hormones / Q000494:pharmacology*
D000960:Hypolipidemic Agents; D013963:Thyroid Hormones; D003577:Cytochrome P-450 Enzyme System; D005993:Glycerolphosphate Dehydrogenase; D044943:Fatty Acid Desaturases; D042964:Acyl-CoA Dehydrogenase; D014453:Glucuronosyltransferase
Influence des états thyroïdiens sur l'induction des enzymes microsomales et peroxysomales par les fibrates chez le rat.