Premium
Tissue norepinephrine depletion as a mechanism for cysteamine inhibition of colon carcinogenesis induced by azoxymethane in wistar rats
Author(s) -
Tatsuta Masaharu,
Iishi Hiroyasu,
Baba Miyako,
Taniguchi Haruo
Publication year - 1989
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.2910440612
Subject(s) - cysteamine , azoxymethane , colorectal cancer , medicine , endocrinology , norepinephrine , carcinogen , aberrant crypt foci , mucin , chemistry , pathology , cancer , biochemistry , colonic disease , dopamine
The effects of cysteamine (2‐aminoethanethiol hydrochloride) on the incidence, number and histology of colon tumors induced by azoxymethane (AOM), and on the norepinephrine concentration in the colon wall tissue and the labelling indices of colon mucosa and colon cancers were investigated in Wistar rats. Rats received 10 weekly injections of 7.4 mg/kg body weight of AOM and alternate‐day subcutaneous injections of 25 mg/kg of cysteamine in 0.9% NaCI solution until the end of the experiment. At week 40, prolonged administration of cysteamine significantly reduced the incidence and number of colon tumors. Histologically, the adenocarcinomas that did develop in rats treated with cysteamine exhibited high mucin‐producing activity. Administration of cysteamine caused significant decreases in the norepinephrine concentration in colon tissue and in the labelling indices of colon mucosa and cancers. Our findings indicate that cysteamine 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.