Colonic endocrine cells in rats with chemically induced colon carcinoma

• Sitohy, B. ^[1] ; El-Salhy, M. ^[1]
  1. [1] Institute of Public Health and Clinical Medicine, Departments of Medicine, Section for Gastroenterology and Hepatology, University Hospital, Umea
• Localización: Histology and histopathology: cellular and molecular biology, ISSN-e 1699-5848, ISSN 0213-3911, Vol. 16, Nº. 3, 2001, págs. 833-838
• Idioma: inglés
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  • Colonic carcinoma was induced in male Sprague-Dawley rats by injecting them with 1,2- dimethylhydrazine dihydrochloride. Control rats were injected with EDTA solution. Tissue specimens of colon from four groups of animals: (i) rats without tumour, (ii) with dysplasia and lymphoid hyperplasia, (iii) with colonic adenocarcinoma, and (iv) controls, were investigated. The colonic endocrine cells were detected by immunocytochemistry and quantified by computerised image analysis. Peptide YY (PYY)- and serotonin-immunoreactive cells were found in the colon of all the groups investigated. There were few somatostatin- or enteroglucagon-immunoreactive cells and no pancreatic polypeptide (PP)-immunoreactive cells in the co lon of any of the groups studied. The density of PYY-immunoreactive cells increased significantly in rats with dysplasia and lymphoid hyperplasia and in rats with colon carcinoma. There was no statistica ll y significant difference as regards cell secretory index (CS I) or nuclear area of PYYimmunoreactive cells in any of treated groups examined.

    Nor was there any statistically significant difference between all treated animal groups and controls, as regards cell density, CSI, or nuclear area of serotoninimmunoreactive cells. The present observations in an animal model of human colon carcinoma support the assumption that neuroendocrine peptides in the gut are involved in the carcinogenesis of colorectal carcinoma.

    However, The nature of the changes in the colonic endocrine cells observed here differed from those in patients w ith colon ca rcinoma, possibly due to a difference between the response of young rats to an induced colon carcinoma and a spontaneously developed carcinoma in elderly humans, or due to a species difference.