Peroxisomal and mitochondrial palmitoyl coenzyme A beta-oxidation activities in rat white adipose tissue and their regulation in hypothyroidism.
A peroxisomal fraction with catalase and CN- -insensitive palmitoyl CoA beta-oxidative activity different from the CN- -sensitive mitochondrial palmitoyl CoA beta-oxidative activity was purified from rat epididymal and perirenal white adipose tissue by differential and sucrose density gradient centrifugations. The degree of purification of this fraction as compared to the nuclei-free and fat-free homogenate was 10 and 34 for catalase and palmitoyl CoA beta-oxidative activity, respectively. The finding that it was devoid of urate oxidase activity suggests that white adipose tissue peroxisomes are anucleoid. The contributions of the peroxisomes and of the mitochondria to total beta-oxidative activity in white adipose tissue were 65 and 35%, respectively. Hypothyroidism induced a 2.0- and 2.4-fold decrease of mitochondrial and peroxisomal beta-oxidation specific activities, respectively. These results are discussed in terms of a possible thermogenic role for white adipose tissue peroxisomes.
D000273:Adipose Tissue / Q000201:enzymology*; D000818:Animals; D002374:Catalase / Q000302:isolation & purification / Q000502:physiology; D002499:Centrifugation, Density Gradient; D007037:Hypothyroidism / Q000201:enzymology*; D008297:Male; D008830:Microbodies / Q000201:enzymology*; D008928:Mitochondria / Q000201:enzymology*; D009940:Organoids / Q000201:enzymology*; D010084:Oxidation-Reduction / Q000187:drug effects; D010088:Oxidoreductases / Q000302:isolation & purification* / Q000502:physiology; D051381:Rats
D010088:Oxidoreductases; D002374:Catalase; C028427:palmitoyl CoA oxidase