Glutathione correlates with lipid peroxidation in liver mitochondria of triiodothyronine-injected hypophysectomized rats.
The temporal relationship of changes in state 3 respiration, lipid peroxidation, and glutathione (GSH) content was investigated in liver mitochondria of hypophysectomized rats after an injection of 3,3',5-triiodo-L-thyronine (T3). Lipid peroxidation induced by ADP/Fe3+/NADPH was determined by the amount of malondialdehyde formed. Hypophysectomy decreased respiration and lipid peroxidation (from 19.88 +/- 3.04 to 14.19 +/- 1.14 nmol malondialdehyde.mg protein-1.10 min-1) but increased GSH content (from 7.06 +/- 2.08 to 12.46 +/- 3.58 nmol/mg protein). Daily injections of a low dose (5 micrograms/100 g) of T3 for 7 days restored the parameters. Time course (up to 96 h) of these changes was followed after one injection of a moderate (100 micrograms/100 g) and high (1000 micrograms/100 g) dose of the hormone. Respiration showed a significant increase at 24 h and declined slightly at 96 h. There was a slow loss of respiratory control ratio after 24 h. Lipid peroxidation remained unchanged at 24 h and showed a gradual increase, becoming significantly higher at 72-96 h depending on the hormone dosage. Changes in GSH content followed a time course similar to that of lipid peroxidation except that it showed a decrease instead of an increase. There was a high degree of inverse linear correlation between lipid peroxidation and GSH (correlation coefficient = 0.95). Because GSH is required for detoxification of hydroperoxides generated by the respiratory chain, it is suggested that lipid peroxidation may play a major role in the modulation of intramitochondrial GSH.
Maddaiah
V T
VT
Department of Pediatrics, Nassau County Medical Center, East Meadow, New York.
D000818:Animals; D005978:Glutathione / Q000502:physiology*; D007016:Hypophysectomy; D015227:Lipid Peroxidation / Q000502:physiology*; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D008930:Mitochondria, Liver / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D014284:Triiodothyronine / Q000494:pharmacology
D014284:Triiodothyronine; D008315:Malondialdehyde; D005978:Glutathione