Insulin does not play the major role in the refeeding stimulation of hepatic ornithine decarboxylase activity.

Pharmacologic doses of insulin stimulate hepatic ornithine decarboxylase activity. In an effort to see if changes of insulin levels in a physiologic range are also stimulatory, we tube fed 3-day fasted rats with pure carbohydrate, protein and fat meals. Only the protein meal was stimulatory in spite of the carbohydrate meal causing the largest increase in plasma insulin.