Induction of ornithine decarboxylase and DNA synthesis in rat stomach mucosa by methylglyoxal.

Administration of methylglyoxal at doses of 300-600 mg/kg body weight by gastric tube to male F344 rats induced 100-fold increase in ornithine decarboxylase activity (formation of 682 pmol CO2/30 min/mg protein) within 7 h, 26-fold increase in DNA synthesis (incorporation of 17 800 d.p.m. of [3H]thymidine/microgram DNA) within 16 h, 16-fold increase in the labeling index of S-phase cells (increase from 1.7 to 26.5) within 16 h, and apparent unscheduled DNA synthesis within 2 h in the glandular stomach mucosa. These results suggest that methylglyoxal has potential promoter activity and may also have initiating activity in carcinogenesis in the glandular stomach.