Inhibition by cysteamine of hepatocarcinogenesis induced by N-nitrosomorpholine in sprague-dawley rats

✍ Scribed by Masaharu Tatsuta; Hiroyasu Iishi; Miyako Baba

• Publisher: John Wiley and Sons
• Year: 1989
• Tongue: French
• Weight: 533 KB
• Volume: 44
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/ijc.2910440326

✦ Synopsis

The effect of cysteamine (2-aminoethanethiol hydrochloride) on hepatocarcinogenesis induced by N-nitrosomorpholine (NNM) was investigated in male Sprague-Dawley rats. Rats received alternate-day S.C. injections of cysteamine, and beginning in experimental week 3 were given drinking water containing N N M for 8 weeks. Pre-neoplastic and neoplastic lesions staining positive for gamma-glutamyl transpeptidase (GGT) or glucose-6-phosphate dehydrogenase (G6PD) were examined by histochemical techniques. In week 18, quantitative histological analysis showed that prolonged administration of cysteamine resulted in a significant reduction in the number of GGT-positive and G6PD-positive hepatic lesions. Histologically, hepatocellular carcinomas were significantly fewer and smaller in GGT-positive and G6PD-positive lesions in rats treated with cysteamine than in untreated rats. Administration of cysteamine also caused a significant decrease in the liver norepinephrine concentration and in the labelling indices of pre-neoplastic lesions and the surrounding liver. Our findings indicate that cysteamine inhibits hepatocarcinogenesis; this may be related to its reducing effect on norepinephrine concentration in the liver and its subsequent inhibition of cell proliferation in neoplastic lesions and surrounding hepatocytes.