Synthesis of VLDL by isolated rat hepatocytes in suspension

Very low density lipoprotein (VLDL) synthesis was studied using suspensions of isolated rat hepatocytes prepared and incubated as described previously (1). These hepatocytes synthesized and secreted VLDL over a 24-hr period, in quantities permitting its isolation, without using carrier, for determining absolute synthesis rates and analysing the peptide pattern. The mean secretion of triglyceride, cholesterol and rat VLDL protein was 410 ± 46.6, 36.6 ± 0.1 and 34.9 ± 5.4 (mean ± SEM, n = 5) μg/g hepatocyte/hr over 24 hr, during which incorporation of 3H-valine into VLDL protein approached linearity. Suitable polyacrylamide gel electrophoresis showed the hepatocytes secreted the peptides found in circulating rat VLDL but with a different proportion of the fast to the slowly migrating ones.