Effect of thyroid hormones and their analogues on the mitochondrial calcium transport activity.
In this paper the authors studied the effects of thyroid hormones and their structural analogues on the mitochondrial calcium transport activities. The thyroid hormones, 3,5,3' L-triiodothyronine (LT3) and 3,5,3'5' L-tetraiodothyronine (LT4) at physiological intracellular concentrations between 7.2 and 9 nM, decouple total Ca++ transport, as well as inhibit the passive transport of Ca++, either due to oxidation of pyruvate, malate or succinate or after inhibition with rotenone. The optical isomers 3,5,3' D-triiodothyronine (DT3) and 3,5,3',5' D-tetraiodothyronine (DT4) are less effective at all the used concentrations. Furthermore the structural analogues 3,3',5' L-triiodothyronine (LrT3), 3,5-dicloro, 3',5' L-diiodothyronine (LDiClT2) and 3,5 L-diiodothyronine (LT2) furnished even less effects on the same activities. The effect of the thyroid hormones and of their structural analogues has revealed that the mitochondrial calcium transport may be influenced both by a stereospecific interaction between hormones and protein ligands and by a lipophilic chaotropic action on the mitochondrial membranes lipids. In this context it is interesting to consider that both thyroid hormones and Ca++ transport activity are interacting with the energetic metabolism by means of phosphorylation and substrate oxidation mechanism.
De Giovanni
R
R
Department of Cell Biology, University of Calabria, Italy.
Asta
L
L
Covello
C
C
Marotta
M
M
Mazzulla
S
S
Parrilla
R
R
Pitrelli
G
G
Spena
A
A
Martino
G
G
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D004734:Energy Metabolism / Q000187:drug effects; D066298:In Vitro Techniques; D008293:Malates / Q000494:pharmacology; D008297:Male; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism*; D009114:Murexide / Q000494:pharmacology; D010084:Oxidation-Reduction; D010085:Oxidative Phosphorylation / Q000187:drug effects; D011773:Pyruvates / Q000494:pharmacology; D019289:Pyruvic Acid; D051381:Rats; D017208:Rats, Wistar; D012402:Rotenone / Q000494:pharmacology; D013386:Succinates / Q000494:pharmacology; D013963:Thyroid Hormones / Q000494:pharmacology*; D013974:Thyroxine / Q000494:pharmacology; D014284:Triiodothyronine / Q000494:pharmacology
D008293:Malates; D011773:Pyruvates; D013386:Succinates; D013963:Thyroid Hormones; D012402:Rotenone; D014284:Triiodothyronine; D009114:Murexide; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; C030298:malic acid; D019289:Pyruvic Acid; D013974:Thyroxine; D002118:Calcium