Peroxisomal beta-oxidation in liver and muscles of gold-thioglucose-induced obese mice: correlation with body weight.
The effect of obesity on peroxisomal beta oxidation has been studied previously only in the liver of genetically obese animals. We measured activity of peroxisomal acyl CoA oxidase (ACO) in livers, hearts and rectus femoris muscles of gold-thioglucose treated obese mice (n = 17) and control mice (n = 8). Since production of H2O2 by ACO could contribute to oxidative stress, activities of H2O2-metabolizing enzymes, catalase and glutathione peroxidase, were also measured. ACO activity was assayed using dichlorofluorescein and peroxidase as detectors of H2O2. ACO activity was higher in the obese liver and skeletal muscles than in their respective controls, while the heart ACO activity was unaltered. The activities of H2O2-metabolizing enzymes were unchanged or tended to be decreased in the obese tissues. There was a close correlation between the body weight and ACO activity in both liver and rectus femoris muscles. The ACO activity in the liver also correlated with the liver triacylglycerol content. These results suggest that the activation of peroxisomal beta oxidation occurring in both hepatic and extrahepatic obese tissues is closely linked to weight gain (i.e. non-genetic in nature), but that this does not enhance oxidative stress detected as reactive change of the defense system against H2O2.
Asayama
K
K
Department of Pediatrics, Yamanashi Medical College, Japan.
Okada
Y
Y
Kato
K
K
D042962:Acyl-CoA Oxidase; D000818:Animals; D006051:Aurothioglucose; D001835:Body Weight / Q000502:physiology*; D002374:Catalase / Q000378:metabolism; D005260:Female; D005979:Glutathione Peroxidase / Q000378:metabolism; D008099:Liver / Q000201:enzymology*; D051379:Mice; D008813:Mice, Inbred ICR; D008830:Microbodies / Q000201:enzymology*; D009132:Muscles / Q000201:enzymology*; D009206:Myocardium / Q000201:enzymology; D009765:Obesity / Q000139:chemically induced / Q000201:enzymology*; D010088:Oxidoreductases / Q000378:metabolism*; D012044:Regression Analysis; D013223:Statistics as Topic
D006051:Aurothioglucose; D010088:Oxidoreductases; D002374:Catalase; D005979:Glutathione Peroxidase; D042962:Acyl-CoA Oxidase