Tissue norepinephrine depletion as a mechanism for cysteamine inhibition of colon carcinogenesis induced by azoxymethane in wistar rats

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

• Publisher: John Wiley and Sons
• Year: 1989
• Tongue: French
• Weight: 488 KB
• Volume: 44
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/ijc.2910440612

✦ Synopsis

The effects of cystearnine (2-arninoethanethiol hydrochloride) on the incidence, number and histology of colon tumors induced by azoxyrnethane (AOM), and on the norepinephrine concentration in the colon wall tissue and the labelling indices of colon rnucosa and colon cancers were investigated in Wistar rats. Rats received I0 weekly injections of 7.4 rng/kg body weight of AOM and alternate-day subcutaneous injections of 25 rnglkg of cystearnine in 0.9% NaCl solution until the end of the experiment. At week 40, prolonged administration of cystearnine significantly reduced the incidence and number of colon tumors. Histologically, the adenocarcinornas that did develop in rats treated with cystearnine exhibited high rnucin-producing activity. Adrninistration of cystearnine caused significant decreases in the norepinephrine concentration in colon tissue and in the labelling indices of colon rnucosa and cancers. Our findings indicate that cystearnine inhibits the development of colon tumors. This action may be related to its effect in decreasing norepinephrine concentration in the colon wall tissues and subsequently in decreasing proliferation of colon cancer cells.