tokens: Mechanistic studies revealed that OB rats are sensitized due to : ( 1 ) higher oxyradical stress leading to upregulation of uncoupling proteins 2 and 3 , ( 2 ) downregulation of cardiac peroxisome proliferators activated receptor - alpha , ( 3 ) decreased plasma adiponectin levels , ( 4 ) decreased cardiac fatty - acid oxidation ( 666 . 9 + / - 14 . 0 nmol / min / g heart in ND versus 400 . 2 + / - 11 . 8 nmol / min / g heart in OB ) , ( 5 ) decreased mitochondrial AMP - alpha2 protein kinase , and ( 6 ) 86 % drop in cardiac ATP levels accompanied by decreased ATP / ADP ratio after doxorubicin administration .