Activation of respiration and loss of thermodynamic control in hyperthyroidism. Is it due to increased slipping in mitochondrial proton pumps?
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 mitochondria at 45 degrees 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.
Luvisetto
S
S
CNR Unit for the Study of Mitochondrial Physiology, University of Padova, Italy.
Schmehl
I
I
Conti
E
E
Intravaia
E
E
Azzone
G F
GF
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D001693:Biological Transport, Active; D006980:Hyperthyroidism / Q000378:metabolism*; D008297:Male; D008928:Mitochondria / Q000378:metabolism*; D010101:Oxygen Consumption; D011188:Potassium / Q000378:metabolism; D011522:Protons; D051381:Rats; D011919:Rats, Inbred Strains; D013696:Temperature; D013816:Thermodynamics; D014284:Triiodothyronine / Q000494:pharmacology
D011522:Protons; D014284:Triiodothyronine; D000251:Adenosine Triphosphatases; D011188:Potassium