Comparative aspects regarding MNU-induced mammary carcinogenesis in immature Sprague-Dowley and Whistar rats

Adrian GAL, Alecsandru BABA, Viorel MICLAUS, Cosmina BOUARI, Marian TAULESCU, Pompei BOLFĂ, Gabriel BORZA, Cornel CATOI


The research carried out on an experimental mammary cancer model by using two breeds of rat, such as Sprague-Dawley (n=10) and Wistar (n=9) female rats. There have been used immature rats that received intraperitonealy a single dose of methyl-nitroso-urea (55 mg/kg MNU). The rats were kept in optimal conditions of temperature, food and hygiene for 8 months. The Wistar rats were sacrificed by deep narcosis with Halothane, and were harvested samples for histopathology exam. The Sprague-Dawley rats were not slaughtered being utilized still to test the efficacy of some antioxidative agents in mammary cancer prevention. In Wistar rats, mammary tumor incidence was reduced representing 33,3% of all cases. In 22,2% of all cases precancerous mammary lesions occurred. On the other hand, MNU generated a great variability of tumor types in various tissues and organs, such as: liposarcoma, nephroblastoma, bronchial gland carcinoma, hemangiosarcoma, squamous carcinoma, sebaceous gland carcinoma, small cell lung carcinoma and lipoma. Comparing to this, in Sprague-Dawley rats mammary tumor incidence following to MNU-intake was 80% of all cases. Concluding, the most appropriate breed of rat that could be utilized as experimental model to study canine and human mammary cancer is Sprague-Dawley.

Full Text:



University of Agricultural Sciences and Veterinary Medicine
3-5 Manastur St., 400372 Cluj-Napoca
Tel: +40-264-596.384 | Fax: +40-264-593.792