Purpose: the morphologic and morphometric aspects of the breasts of rats in permanent estrus submitted to danazol were studied. Methods: the animals were divided into three groups: group A (n = 12) received water and was used as control, group B (n = 13) was exposed to 20 mg danazol kg-1 day-1, and group C (n = 10) was exposed to 80 mg danazole kg-1 day-1 for 35 consecutive days. The microscopic study evaluated the ductal and acinar distribution. Histometry of the relationship duct/stroma was based on the principles of stereology with a Zeiss k-10X ocular, with Integrationsplatte I reticulum of Weibel of 25 hits, with 100X magnification. For each studied section, 10 aleatoric fields were counted, with a total of 250 points. The variance analysis test (Kruskal-Wallis) was applied to compare the three groups in relation to the mean number of alveoli and ducts (alpha = 0.05). Results: when submitted to morphological study, all groups presented lobules with alveoli lined with cubic cells with nuclei in their central or basal portion. Small amounts of eosinophilic material were observed in some cases in the lumen, with no differences between the groups. At morphometry, with a magnification of 100X, a mean number of 28.6 ducts/10 fields was found in group A, 28.4 in group B and 29.2 in group C (Kruskal-Wallis test: Hcrit = 0.1). The mean number of alveoli in 10 fields was 5.9, 9.3 and 6.5 in groups A, B and C, respectively (Kruskal-Wallis test: Hcrit = 2.9), with no significant differences between the groups. Conclusion: danazol did not cause any changes in the morphology and morphometry of the permanent estrus mammary epithelium.
Danazol; Breast; Mastalgia
