Inductions of Ornithine Decarboxylase and Replicative DNA Synthesis but not DNA Single Strand Scission or Unscheduled DNA Synthesis in the Pyloric Mucosa of Rat Stomach by Catechol

The possible tumor‐promoting and genotoxic activities of catechol were examined. Administration of catechol by gastric intubation at doses of 10 to 90 mg/kg body weight to male F344 rats induced up to 19‐fold increase in ornithine decarboxylase activity with a maximum after 8 h and up to 8‐fold increase in replicative DNA synthesis with a maximum after 24 h in the pyloric mucosa of the stomach. These results suggest that catechol has tumor‐promoting activity in the pyloric mucosa of rat stomach. However, its administration at doses of 37.5 to 90 mg/kg body weight did not induce DNA single strand scission in the pyloric mucosa as determined by the alkaline elution method after 2 and 6 h or unscheduled DNA synthesis examined after 2 and 12 h.