Activation of respiration and loss of thermodynamic control in hyperthyroidism Is it due to increased slipping in mitochondrial proton pumps?

FEBS Letters

Azzone, Giovanni Felice¹  Conti, Elena¹  Intravaia, Elena¹  Schmehl, Ibolya¹  Luvisetto, Siro¹ 

[1] CNR Unit for the Study of Mitochondrial Physiology and Institute of General Pathology, University of Padova, via Trieste 75, I-35121 Padova, Italy

关键词: Mitochondria;    Hyperthyroidism;    Temperature;    Thermodynamics;    Uncoupling;    Slipping;    T3;    3;    3;    5-triiodo-L-thyronine;    Δp;    proton-motive force;    Δψ;    transmembrane electrical potential gradient;    or ‘Nernst diffusion potential’;    J o;    rate of respiration in state 4;    J K+;    rate of K+ efflux;    J ATP;    rate of ATP hydrolysis;    Ap5A;    P1;    Ps-di(adenosine-5′)-pentaphosphate;   

DOI  :  10.1016/0014-5793(91)81093-N

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

T₃ administration increases the extent of non-linearity in the flow—force relationship between pump proton conductance and protonmotive force. The effect is present also at the ATPase proton pump. These effects are not accompanied by changes in passive proton conductance. Incubation of mitocondria at 45°C also causes an increased non-linearity, accompanied by a partial increase of proton conductance. It appears that the increase of respiratory activity following T₃ administration is due to loss of thermodynamic control within or at the proton pumps, an effect which might be attributed to increased slipping.

【 授权许可】

Unknown