Biologia, Bratislava, 55/Suppl. 8: 63-67, 2000.

ISSN 0006-3088 (Biologia). ISSN 1335-6399 (Biologia. Section Cellular and Molecular Biology).


Full Paper

mammary tumours in female rats developed after 1-methyl-1-nitrosourea treatment.


Jan Liska1, Stefan Galbavy2, Jozef Zlatos1, Danica Macejova3, Maria Micincova1 & Julius Brtko3*

1 Inistitute of Histology and Embryology, Medical Faculty, Comenius University, Sasinkova 4, SK-81108 Bratislava, Slovakia

2 Institute of Pathological Anatomy, Medical Faculty, Comenius University, Sasinkova 4, SK-81108 Bratislava, Slovakia

3 Institute of Experimental Endocrinology, Slovak Academy of Sciences, Vlarska 3, SK-83306 Bratislava, Slovakia; e-mail:

* corresponding author

Received: July 10, 2000 / Accepted: October 24, 2000



Female Sprague–Dawley adult rats were administered intraperitoneally with 5 doses of 50 body weight 1-methyl-1-nitrosourea (MNU) in the first experiment and with 2 doses (one dose per two months) of MNU in the second experiment. On the 117th day in the first experiment and on the 153rd day of age in the second experiment rats were killed by decapitation and their mammary glands were evaluated morphologically for the presence of mammary tumours. All excised tissues were stained with hematoxylin and eosin and were evaluated histochemically for the presence of actin and S-100 protein. All microscopically evaluated tumours were malignant. Of the total number of lesions classified the percentage of invasive tumours was in the range of 35-44%. No metastases were observed in other organs.


Key words: 1-methyl-1-nitrosourea, Sprague-Dawley rat, histopathology, mammary carcinoma.