Phosphorylation of carnitine palmitoyltransferase and activation by glucagon in isolated rat hepatocytes

Publisher Website
Google Scholar
Abstract
Effects of glucagon and forskolin on the phosphorylation and changes of activity of carnitine palmitoyl-transferase (CPT) have been studied in isolated rat hepatocytes using anti-CPT immunoglobulin. When the activity was determined in lysed hepatocytes after glucagon or forskolin treatment, it was found to be stimulated 30–80% mainly through increased affinity for palmitoyl-CoA. By SDS electrophoresis of the immuno-precipitates, CPT subunit (M r 69000) was noted to be phosphorylated 4–5-fold with glucagon (1.2 × 10−7 M) and forskolin (0.1 mM) over control. These results indicate that hepatic ketogenesis is regulated with glucagon by phosphorylation of CPT through cAMP-dependent protein kinase.