The effect of alpha-difluoromethylornithine on ornithine decarboxylase activity in compensatory growth of mouse lung.

After removing the left upper lobe, the remaining lung of mice undergoes compensatory growth. Increased ornithine decarboxylase activity is characteristic of the process. The effect of alpha-difluoromethylornithine was studied on the ornithine decarboxylase (E.C.4.1.1.17.) activity and on the lung growth in mice after lobectomy. Although a single injection of alpha-difluoromethylornithine inhibited ornithine decarboxylase activity, the compensatory growth of lung still occurred in spite of continuous alpha-difluoromethylornithine treatment. This suggests that polyamines, indispensable for compensatory growth, may be supplied by other sources.