Kuroiwa, Yuichi and Okamura, Toshiya and Ishii, Yuji and Umemura, Takashi and Tasaki, Masako and Kanki, Keita and Mitsumori, Kunitoshi and Hirose, Masao and Nishikawa, Akiyoshi (2008) Enhancement of esophageal carcinogenesis in acid reflux model rats treated with ascorbic acid and sodium nitrite in combination with or without initiation. CANCER SCIENCE, 99 (1). pp. 7-13. ISSN 1347-9032
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Official URL: http://www3.interscience.wiley.com/journal/1194156...
Combined treatment with sodium nitrite (NaNO2) and ascorbic acid (AsA) has already been shown to promote rat forestomach carcinogenesis, possibly due to nitric oxide generation under acidic conditions. We hypothesized that a similar effect might occur in the esophagus when the luminal pH is decreased by acid reflux. To clarify this possibility, reflux esophagitis model rats (F344 male) were coadministered 0.2% NaNO2 in the drinking water and 1% AsA in the diet. After 32 weeks of the combined treatment, a significant increase in the incidence of epithelial hyperplasias of the lower-middle and lowest parts of the esophagus were observed compared with the basal-diet group, along with exacerbation of dysplasia and extension of the lesions. Additionally, one squamous cell papilloma was found only in the combined-treatment group. Subsequently, we confirmed the enhancing effects of NaNO2 and AsA cotreatment in the rat N-bis(2-hydroxypropyl)nitrosamine-initiated esophageal tumorigenesis model. The incidence of hyperplasia was enhanced in all segments, along with the incidence and multiplicity of squamous cell papillomas in the lowest segment of the esophagus. Thus, the data demonstrate that combined treatment with NaNO2 and AsA exerts promoting effects on rat esophageal carcinogenesis under acid reflux conditions, as in the forestomach. These findings suggest that the risk of excessive intake of a combination of nitrite and antioxidants for esophageal carcinogenesis is appreciable, particularly in patients with reflux esophagitis.
|Subjects:||Biomedical Science > Nanobiotechnology|
|Deposited By:||M T V|
|Deposited On:||09 Dec 2008 10:49|
|Last Modified:||09 Dec 2008 10:49|
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