Tumor-promoting activity of 2,6-dimethylaniline in a two-stage nasal carcinogenesis model in N-bis(2-hydroxypropyl)nitrosamine-treated rats.

Abstract

The potential promotion activity on nasal carcinogenesis of 2,6-dimethylaniline (DMA), an alpha2-adrenergic agonist metabolite of xylazine which is used for food-producing animals as a sedative agent, was examined. Male F344 rats received diet containing 0 or 3000 ppm DMA for 52 weeks after initiation with N-bis(2-hydroxypropyl)nitrosamine (DHPN). Histopathological assessment showed the incidence of carcinomas in the DHPN+DMA group (33%) to be significantly elevated as compared with that for the DHPN-alone group (5%). Incidences and/or multiplicity of epithelial hyperplasias and dysplastic foci were also increased in the DHPN+DMA group. These lesions were exclusively observed in the olfactory mucosa. The lowest plasma levels of DMA in tumor- and dysplastic foci-bearing rats were 0.05 and 0.20 microg/ml, respectively. These results indicate that DHPN acts as an appropriate initiator for nasal carcinogenesis and that DMA exerts a tumor-promoting effect on the olfactory mucosa in the rat nasal cavity.

• Authors: T Koujitani, K Yasuhara, H Kobayashi, A Shimada, H Onodera, H Takagi, M Hirose, K Mitsumori
• Journal: Cancer letters (Cancer Lett) Vol. 142 Issue 2 Pg. 161-71 (Aug 03 1999) ISSN: 0304-3835 [Print] Ireland
• PMID: 10463772 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Adrenergic alpha-Agonists
• Aniline Compounds
• Carcinogens
• Nitrosamines
• 2,6-xylidine
• diisopropanolnitrosamine

Topics

• Adenoma (blood, chemically induced, pathology)
• Adrenergic alpha-Agonists (pharmacology)
• Aniline Compounds (blood, pharmacology)
• Animals
• Carcinogens (pharmacology, toxicity)
• Carcinoma (blood, chemically induced, pathology)
• Drug Synergism
• Male
• Nasal Mucosa (drug effects, pathology)
• Nitrosamines (toxicity)
• Nose Neoplasms (blood, chemically induced, pathology)
• Rats
• Rats, Inbred F344
• Turbinates (drug effects, pathology)