Enhancement by tyrosine methyl ester of gastric carcinogenesis induced by N-methyl-N′-nitro-N-nitrosoguanidine in wistar rats

✍ Scribed by Masaharu Tatsuta; Hiroyasu Iishi; Miyako Baba; Haruo Taniguchi

• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: French
• Weight: 471 KB
• Volume: 48
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/ijc.2910480525

✦ Synopsis

The effect of tyrosine methyl ester (TME) on the incidence, number, and histological types of gastric cancers induced by N-methyl-N'-nitro-N-nitroroguanidine (MNNG) was investigated in male Wistar rats. Rats were subcutaneously given TME, 5 I 2 mg/kg body weight, every other day after 20 weeks of oral treatment with MNNG. Prolonged alternate-day administration of TME caused a significant increase in the incidence and number of gastric cancers of the glandular stomach by week 52. However, it did not affect the histology of the cancers. TME also caused a significant increase in tissue norepinephrine concentrations in the antral portion of the gastric wall and in the labelling indices of the antral epithelial cells.

However, TME had no influence on the serum gastrin level and antral PH. These findings indicate that TME enhances gastric carcinogenesit, and this may be related to its effects on increasing norepinephrine levels in the gastric wall and stimulating proliferation of the antral epithelial cells.