Protection by galanin against gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats.

The effects of prolonged administration of the neuropeptide galanin on gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine, the norepinephrine concentration in the gastric wall, and the labeling index of the gastric mucosa were investigated in Wistar rats. The rats received 2 or 4 micrograms/kg body weight of galanin s.c. every other day after 25 weeks oral treatment with the carcinogen. Prolonged administration of galanin at 4 micrograms/kg body weight, but not at 2 micrograms/kg body weight, significantly decreased the incidence of gastric cancers in experimental week 52. However, it did not influence the histological types of cancers. Galanin at 4 micrograms/kg body weight also significantly decreased the labeling index of the antral epithelial cells but not the norepinephrine concentration in the gastric wall. These findings indicate that galanin inhibits gastric carcinogenesis and suggest that its effect may be related to the suppression of proliferation of the antral epithelial cells.