Intramitochondrial reductive carboxylation of 2-oxoglutarate in adipose tissue and its contribution to fatty acid synthesis.
The reductive carboxylation of 2-oxoglutarate was found to proceed in mitochondria of rat epididymal fat pads and rabbit perirenal adipose tissue at a rate similar to that in liver mitochondria. In rat fat pads the incorporation of 14C from [5-14C]2-oxoglutarate into fatty acids via the carboxylation was suppressed by butylmalonate by 30%. 2-Oxoglutarate and glutamate stimulated the incorporation into fatty acids of 14C from [2-14C]acetate in rat fat pads with the simultaneous reduction of tissue NADP. These effects persisted after inhibition of succinate dehydrogenase by malonate. It is concluded that in adipose tissue 2-oxoglutarate carboxylation proceeds in both the cytoplasm and mitochondria. Therefore, it can supply carbon atoms as well as NADPH for fatty acid synthesis.
D000085:Acetates / Q000378:metabolism; D019342:Acetic Acid; D000255:Adenosine Triphosphate / Q000378:metabolism; D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D002250:Carbon Radioisotopes; D005227:Fatty Acids / Q000096:biosynthesis*; D005947:Glucose / Q000378:metabolism; D005994:Glycerophosphates / Q000378:metabolism; D007656:Ketoglutaric Acids / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D008928:Mitochondria / Q000378:metabolism*; D008930:Mitochondria, Liver / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D010084:Oxidation-Reduction; D051381:Rats; D011919:Rats, Inbred Strains
D000085:Acetates; D002250:Carbon Radioisotopes; D005227:Fatty Acids; D005994:Glycerophosphates; D007656:Ketoglutaric Acids; D009249:NADP; D000255:Adenosine Triphosphate; C029620:alpha-glycerophosphoric acid; D005947:Glucose; D019342:Acetic Acid