Influence of genetic obesity, food intake and adrenalectomy in mice on selected trace element-dependent protective enzymes.
Experiments were conducted to determine if food intake and adrenalectomy influenced abnormal antioxidant defense mechanisms observed in obese mice. Paired male C57BL/6J mice of two genotypes, obese (ob/ob) and lean (+/?), were fed a nonpurified diet ad libitum or restricted (2.5 g/d) until 3 mo old. Obese mice had larger livers and kidneys but smaller brains than lean mice. Plasma ceruloplasmin activity of obese mice was 240% of that of lean mice. Restricting food intake but not adrenalectomy reduced this difference, but ceruloplasmin activity of obese mice was still 150% of that of restricted-fed lean mice. Glutathione peroxidase (GSH-Px) activity in liver of obese mice was 70% of that in control lean mice; however, in kidney GSH-Px activity was 135% of that in obese mice. Both liver and kidney GSH-Px differences were eliminated by food restriction but not by adrenalectomy. Blood and brain GSH-Px activity was not influenced by the mutation. Liver and kidney copper-zinc superoxide dismutase activity was lower in obese mice than in lean littermates, 30 and 20%, respectively. Food restriction eliminated this difference in liver but not in kidney. Glutathione S-transferase activity using 1-chloro-2,4-dinitrobenzene as substrate was 55% lower in liver (not kidney) of obese mice than in lean mice and this difference was not markedly influenced by food restriction. Obese mice have marked changes in the steady-state activities of a number of protective enzymes that are organ dependent and, in part, due to the hyperphagia associated with this mutation.
Prohaska
J R
JR
Department of Biochemistry, School of Medicine, University of Minnesota, Duluth 55812.
Wittmers
L E
LE
Haller
E W
EW
D000311:Adrenal Glands / Q000502:physiology*; D000315:Adrenalectomy; D000818:Animals; D001921:Brain / Q000378:metabolism; D002570:Ceruloplasmin / Q000378:metabolism; D004798:Enzymes / Q000378:metabolism*; D005508:Food Deprivation / Q000502:physiology*; D005786:Gene Expression Regulation; D005979:Glutathione Peroxidase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008820:Mice, Obese; D009765:Obesity / Q000201:enzymology / Q000235:genetics*; D009929:Organ Size; D013482:Superoxide Dismutase / Q000378:metabolism; D014131:Trace Elements / Q000502:physiology*
D004798:Enzymes; D014131:Trace Elements; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D002570:Ceruloplasmin; D005982:Glutathione Transferase