The epididymis is an organ that plays a key role in sperm maturation. The aim of this study was to examine the association between the chronic treatment of mature male rats with letrozole and morphological evaluation and morphometric values of epididymis as well as changes in the number of apoptotic cells in epididymal epithelium. Adult rats were treated with letrozole for 6 months and the epididymis weight, morphology, morphometric values and the number of apoptotic cells in the epithelium were examined. Long-term aromatase inhibition resulted in presence of intraepithelial clear vacuoles, hyperplasia of clear cells and a hyperplastic alteration in the epithelium known as a cribriform change. Moreover, changes in diameters of the epididymal duct and the epididymal lumen and changes in the epididymal epithelium height were observed. The number of apoptotic epithelial cells was increased in letrozole-treated group. It can be indicated that chronic treatment with letrozole can affect morphology, morphometric values and apoptosis in the epididymis of adult male rats. Observed changes are similar to that observed in the aging processes and may also be important for patients treated with aromatase inhibitors.

附睾是在精子成熟中起关键作用的器官。本研究的目的是探讨来曲唑长期治疗成年雄性大鼠与附睾形态学评估和形态测量值以及附睾上皮细胞凋亡细胞数量变化之间的关系。成年大鼠用来曲唑治疗6个月，检测附睾重量、形态、形态测量值和上皮细胞凋亡细胞数。长期芳香酶抑制导致上皮内透明空泡的存在、透明细胞的增生和上皮的增生性改变（称为筛状改变）。此外，观察附睾管和附睾管腔的直径变化以及附睾上皮高度的变化。来曲唑治疗组凋亡上皮细胞数量增加。表明来曲唑长期治疗可影响成年雄性大鼠附睾的形态、形态测量值和细胞凋亡。观察到的变化与衰老过程中观察到的变化相似，对于接受芳香酶抑制剂治疗的患者也可能很重要。