Changes in brown-adipose-tissue mitochondrial processes in streptozotocin-diabetes.
Diabetic rats were used as a source of brown-adipose-tissue mitochondria 2 days after a single subcutaneous injection of streptozotocin (100 mg/kg). Diabetes caused an 80% decrease in carnitine-dependent oxidation of palmitoyl-CoA and a 50-60% decrease in overt carnitine palmitoyltransferase activity. An additional lesion in brown-adipose-tissue mitochondrial oxidative capacity was also indicated, since diabetes increased by 30-50% the rate of oxidation under uncoupled conditions of several respiratory substrates (i.e. malate + palmitoylcarnitine, malate + pyruvate, succinate, NNN'N'-tetramethyl-p-phenylenediamine + ascorbate). This decrease in mitochondrial function was accompanied by an approx. 30% decrease in the abundance of cytochromes (a + a3) and total cytochromes b.
Department of Biochemistry, University College London, U.K.
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Jamal
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Saggerson
D002001:Adipose Tissue, Brown / Q000201:enzymology / Q000378:metabolism*; D000818:Animals; D002334:Carnitine O-Palmitoyltransferase / Q000378:metabolism; D003580:Cytochromes / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000201:enzymology / Q000378:metabolism*; D007527:Isoenzymes / Q000378:metabolism; D008297:Male; D008928:Mitochondria / Q000201:enzymology / Q000378:metabolism; D010101:Oxygen Consumption; D051381:Rats; D011919:Rats, Inbred Strains
D003580:Cytochromes; D007527:Isoenzymes; D002334:Carnitine O-Palmitoyltransferase