[Effect of hypothyroidism on mitochondrial energy metabolism and nuclear synthesis of RNA in the liver of Cynomolgus monkeys].
The effects of hypothyroidism and of replacement therapy with T4 or T3 were studied on the enzymatic activities of liver subcellular fractions isolated from Cynomolgus monkeys. Animals were sacrificed 20 days after thyroidectomy. In mitochondria, thyroidectomy decreased significantly the respiratory chain activity (succinate cytochrome c-reductase), the transfer of cytosolic reducing equivalents (glycerol-3-phosphate dehydrogenase) and the phosphorylating capacity (oligomycin-sensitive ATPase and state 3 respiratory rate). The activity of nucleolar and nucleoplasmic RNA polymerases dropped by about 50% in hypothyroid monkeys. In T4 (2.5 micrograms/kg/d) or T3 (1 microgram/kg/d) treated thyroidectomized animals, the iodothyronine concentrations and the activity of mitochondria and nuclei enzymes were halfway between normal and hypothyroid values. Thus, the mitochondrial effects of thyroidectomy in monkey are, as in rat, at least partly secondary to a decrease in nucleocytoplasmic protein synthesis.
Clot
J P
JP
Baudry
M
M
Michel
O
O
Michel
R
R
D000818:Animals; D002467:Cell Nucleus / Q000201:enzymology / Q000378:metabolism; D004734:Energy Metabolism; D007037:Hypothyroidism / Q000378:metabolism*; D008099:Liver / Q000201:enzymology / Q000378:metabolism*; D008252:Macaca fascicularis; D008297:Male; D008930:Mitochondria, Liver / Q000201:enzymology / Q000378:metabolism; D012313:RNA / Q000096:biosynthesis*; D013963:Thyroid Hormones / Q000502:physiology
D013963:Thyroid Hormones; D012313:RNA
Influence de l'hypothyroïdie sur le métabolisme énergétique mitochondrial et la synthèse nucléaire des ARN dans le foie du singe Cynomolgus.