Higher incidence of sperm granuloma in the epididymis of C57BL/6N mice

Abstract

C57BL/6N mice are inbred strains widely used in biomedical research. Hence, a large amount of basic data has been accumulated. However, in the field of histopathology, spontaneous data for relatively younger mice that are used more frequently are not yet abundant, in contrast to data for older mice and their neoplastic lesions. To acquire the essential background data required by various research and toxicological assessments, 120 mice of the C57BL/6N strain (10 and 13 weeks of age) were collected from two institutions (From Korea and Japan) and subjected to histopathological analyses of the major organs (liver, spleen, kidney, thymus, heart, testis, epididymis). The results showed significantly higher incidence of sperm granulomas in the epididymides (10-56%) of these mice, compared with that in other strains or species of lab animals. Upon closer inspection, oligospermia/clear cell hyperplasia, cellular debris, and tubular vacuolation were also observed in the epididymides with sperm granulomas. Moreover, diseased organs were significantly heavier than healthy ones. Immunohistochemical staining showed a significant increase in the chromatic figures of cysteine-dependent aspartate-directed proteases-3 (caspase-3) and cleaved-poly(ADP-ribose) polymerase (c-PARP), and damages to the tubule due to spontaneous apoptosis, which may have led to the sperms leaking out of the tubule, causing the granuloma. To conclude, spontaneous sperm granuloma can occur in 10- and 13-week-old C57BL/6N mice and may thus affect the results of various studies using these mice. Therefore, sperm granuloma in epididymis needs to be carefully considered as an important factor when design the study using C57BL/6N.

MRI features of testicular spermatic granuloma

“…Spermatic granulomas are common in young and middle-aged men. Park et al [10] found that the incidence of spermatic granuloma at a young age is higher than that at an old age in mouse experiments, indicating that the incidence of spermatic granuloma is related to age. The patient in this study was a middle-aged male.…”

To the Issue of Plasticity of Basal Cells of the Epididymal Epithelium

“…. Повреждение структурных компонентов гемато-эпидидимального барьера приводит к развитию инфертильных состояний и формированию спермальных гранулем [1, 15,19,32]. Повреждения эпителия эпидидимиса могут быть вызваны повышением давления семенной жидкости (обтурационные повреждения), а также в результате действия внешних факторов, таких, как бактериальная инфекция, воспаление, химические агенты и лекарственные препараты [1,12,15,19,27,30,37].…”