Thyroid status is a key regulator of both flux and efficiency of oxidative phosphorylation in rat hepatocytes. - Archive ouverte HAL Access content directly
Journal Articles Journal of Bioenergetics Year : 2002

Thyroid status is a key regulator of both flux and efficiency of oxidative phosphorylation in rat hepatocytes.

(1) , (1) , (2) , (1) , (2) , (1)
1
2

Abstract

Thyroid status is crucial in energy homeostasis, but despite extensive studies the actual mechanism by which it regulates mitochondrial respiration and ATP synthesis is still unclear. We studied oxidative phosphorylation in both intact liver cells and isolated mitochondria from in vivo models of severe not life threatening hyper- and hypothyroidism. Thyroid status correlated with cellular and mitochondrial oxygen consumption rates as well as with maximal mitochondrial ATP production. Addition of a protonophoric uncoupler, 2,4-dinitrophenol, to hepatocytes did not mimic the cellular energetic change linked to hyperthyroidism. Mitochondrial content of cytochrome oxidase, ATP synthase, phosphate and adenine nucleotide carriers were increased in hyperthyroidism and decreased in hypothyroidism as compared to controls. As a result of these complex changes, the maximal rate of ATP synthesis increased in hyperthyroidism despite a decrease in ATP/O ratio, while in hypothyroidism ATP/O ratio increased but did not compensate for the flux limitation of oxidative phosphorylation. We conclude that energy homeostasis depends on a compromise between rate and efficiency, which is mainly regulated by thyroid hormones.
Not file

Dates and versions

inserm-00389979 , version 1 (30-05-2009)

Identifiers

  • HAL Id : inserm-00389979 , version 1
  • PUBMED : 11860181

Cite

Véronique Nogueira, Ludivine Walter, Nicol Avéret, Eric M. Fontaine, Michel Rigoulet, et al.. Thyroid status is a key regulator of both flux and efficiency of oxidative phosphorylation in rat hepatocytes.. Journal of Bioenergetics, 2002, 34 (1), pp.55-66. ⟨inserm-00389979⟩

Collections

INSERM UGA CNRS
72 View
0 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More