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Spermatic granulomata are experimentally induced in epididymides of mice receiving high-dose testosterone implants.
M Itoh1, K Miyamoto, I Satriotomo
1Department of Anatomy, Kagawa Medical University, Japan. seiyu@kms.ac.jp
Abstract:
It is known that a spermatic granuloma is induced by the inflammatory reaction following leakage of spermatozoa outside the germ cell ducts and is the main clinical complication of vasectomy. In the present study, we found that spermatic granulomata were experimentally induced in the epididymides of mice treated with high-dose testosterone. Testosterone powder (0.02, 0.2, or 2 mg per gram body weight) was implanted into ICR male mice, which were then killed from 7 to 63 days after the treatment for histological examination at the light-microscopic level. The results showed that the testis exhibited little or no degenerative change; however, the epididymides were frequently affected by spermatic granulomata after day 35 in mice implanted with high-dose testosterone (2 but not 0.2 or 0.02 mg per gram body weight). Observation of the early histological changes revealed that the ductal epithelium of the epididymides became vacuolated around day 25. Thereafter, the basement membrane of the epididymal ducts was ruptured after day 30, followed by leakage of spermatozoa into the adjacent interstitial tissue. The extravasated spermatozoa were then surrounded by macrophages (= epithelioid cells) and lymphocytes, resulting in the formation of a spermatic granuloma. In contrast, other mice treated with the same dose of deoxycorticosterone or estradiol did not show the induction of spermatic granulomata. Therefore, this study demonstrated that a spermatic granuloma is specifically formed in the epididymis by testosterone and that the lesion is started by vacuolation of the epididymal duct epithelium.
Insights
High-dose testosterone experimentally induced spermatic granulomas in mouse epididymides, a key complication of vasectomy. The study identified ductal epithelium vacuolation as the initial step in spermatic granuloma formation.
Area of Science:
- Reproductive biology
- Pathology
- Endocrinology
Background:
- Spermatic granuloma, an inflammatory reaction to leaked spermatozoa, is a primary complication of vasectomy.
- Understanding the specific induction mechanisms of spermatic granuloma is crucial for reproductive health research.
Purpose of the Study:
- To investigate the experimental induction of spermatic granulomas in mice using testosterone.
- To elucidate the early histological changes leading to spermatic granuloma formation in the epididymis.
Main Methods:
- ICR male mice were implanted with varying doses of testosterone (0.02, 0.2, or 2 mg/g body weight).
- Histological examination of testes and epididymides was performed at light-microscopic levels from 7 to 63 days post-treatment.
- Control groups received deoxycorticosterone or estradiol to assess specificity.
Main Results:
- High-dose testosterone (2 mg/g) induced spermatic granulomas in epididymides after 35 days; lower doses did not.
- Testicular tissue showed minimal degenerative changes.
- Early changes included vacuolation of epididymal duct epithelium around day 25, followed by basement membrane rupture and sperm leakage by day 30.
Conclusions:
- Testosterone specifically induces spermatic granulomas in the epididymis, distinct from other steroid effects.
- The formation process begins with vacuolation of the epididymal duct epithelium, leading to sperm extravasation and granuloma development.
- These findings provide a mechanistic understanding of a significant clinical complication of vasectomy.