Ornithine Decarboxylase Activity: Control by Cyclic Nucleotides

Both exposure to cold and administration of aminophylline result in rapid increases in cyclic adenosine monophosphate (cyclic AMP) in the adrenal medulla and adrenal cortex. These increases are followed by dramatic increases in ornithine decarboxylase activity. Inhibitor studies suggest that the increase in ornithine decarboxylase activity is due to new enzyme synthesis. The data suggest that the decarboxylase activity is regulated by an increase in cyclic AMP.