1. Homogenates of subcutaneous adipose tissue from obese subjects contained sufficient citrate cleavage enzyme (EC 126.96.36.199: ATP—citrate oxaloacetate lyase), acetyl-CoA carboxylase (EC 188.8.131.52: acetyl-CoA—carbon dioxide ligase) and fatty acid synthetase to account for the rates of fatty acid synthesis reported in the literature for intact tissues in vitro.
2. The distribution of label in fatty acids after incubations of adipose tissue with [1-14C]acetate was consistent with fatty acid synthesis de novo, not chain elongation.
3. The activities of citrate cleavage enzyme and fatty acid synthetase in subcutaneous adipose tissue were reduced by short periods of starvation.
4. These findings indicate that human adipose tissue is capable of fatty acid synthesis de novo and that two of the enzymes concerned adapt to starvation.