Induction of ornithine decarboxylase activity in epidermis by a tumor promoter: Decreased response in mice maintained on a vitamin B 6-deficient diet

Abstract

Summary Epidermal ornithine decarboxylase (EC 4.1.1.17; L-ornithine carboxy-lyase) activity was rapidly induced after the treatment of mouse skin with 12-O-tetradecanoyl phorbol-13-acetate. Induction was significantly decreased in animals maintained for 10–14 days on a vitamin B 6 -deficient diet, and could be completely restored by the injection of deficient animals with pyridoxine. As predicted, decarboxylase activity in epidermal extracts was sensitive to proteolytic attack (trypsin) in the absence of pyridoxal 5′-phosphate, and was protected from attack by the presence of the cofactor.