Lipogenesis in primary cultures of adipoblasts derived from genetically obese Zucker rats.

Adipocyte precursor cultures prepared from the epididymal fat pads of genetically obese (fa/fa) and lean (Fa/Fa) Zucker rats grow similarly in culture. Addition of enriched medium (EM) containing human serum, insulin, and glucose stimulated lipid filling of the adipocyte precursors in both cultures. However, [3H] H2O incorporation into total lipids, fatty acid synthetase and lipoprotein lipase activities, and cytosolic protein contents are all decreased in the fa/fa compared with the Fa/Fa cultures. Substitution of lean or obese rat serum for human serum in the enriched medium does not alter the decreased lipogenic capacity of the fa/fa adipocyte precursor cultures.