Increase in Ornithine Decarboxylase Activity Caused by Hepatocyte Growth Factor in Primary Cultured Adult Rat Hepatocytes

Abstract

The effect of hepatocyte growth factor on ornithine decarboxylase activity was studied in primary cultured adult rat hepatocytes. Ornithine decarboxylase activity was increased 3 hr after the addition of hepatocyte growth factor and remained at a high level until 12 hr; thereafter it decreased, and it returned to the control level by 24 hr. Enzyme activity began to increase with 1 ng/ml hepatocyte growth factor and reached its maximum with 5 ng/ml hepatocyte growth factor. When insulin or epidermal growth factor was added with hepatocyte growth factor, enzyme activity was further stimulated. The level of ornithine decarboxylase messenger RNA did not increase with addition of hepatocyte growth factor. The half-time of ornithine decarboxylase activity was prolonged about twofold by hepatocyte growth factor treatment. These results suggest that hepatocyte growth factor treatment of cells enhanced ornithine decarboxylase activity posttranslationally.