Influence of hyperthyroidism on superoxide radical and hydrogen peroxide production by rat liver submitochondrial particles.
Administration of daily doses of 0.1 mg of 3,5,3'-triiodothyronine (T3)/kg body weight for 3 consecutive days to fed rats elicited a calorigenic response in the animals, in concomitance with a 36% increase in the rate of 0(2) consumption by the liver. In these conditions, liver submitochondrial particles (SMP) from T3-treated rats exhibited marked increases in the rate of superoxide radical generation, both in the presence of NADH (142%) or succinate (152%). Furthermore, liver SMP from hyperthyroid animals released hydrogen peroxide at higher rates than those of euthyroid rats, either under basal conditions or in the succinate-supported process, both in the absence and presence of antimycin-A. It is concluded that the hyperthyroid state in the rat leads to a drastic enhancement in the capacity of liver mitochondria to produce active oxygen species, which correlates with the elevated respiratory rate observed in the intact organ.
Departamento de Bioquímica, Facultad de Medicina, Universidad de Chile, Casilla, Santiago.
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Fernández
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Videla
D000818:Animals; D006861:Hydrogen Peroxide / Q000378:metabolism*; D006980:Hyperthyroidism / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D013367:Submitochondrial Particles / Q000187:drug effects / Q000378:metabolism*; D013481:Superoxides / Q000378:metabolism*; D014284:Triiodothyronine / Q000494:pharmacology
D014284:Triiodothyronine; D013481:Superoxides; D006861:Hydrogen Peroxide