Quantitation of sperm disposal and phagocytic cells in the tract of short- and long-term vasectomized mice

Area of Science:

• Reproductive Biology
• Urology
• Cell Biology

Background:

• Vasectomy is a common male sterilization procedure.
• Understanding sperm fate post-vasectomy is crucial for reproductive health research.
• The mechanisms of sperm disposal in the male reproductive tract remain incompletely understood.

Purpose of the Study:

• To quantify sperm resorption rates in mice after vasectomy.
• To investigate the cellular mechanisms involved in sperm disposal post-vasectomy.
• To compare the roles of phagocytosis and intraluminal dissolution in sperm breakdown.

Main Methods:

• Spermatozoa production in testes was calculated post-vasectomy.
• Spermatozoa counts in epididymides and vasa deferentia were performed at various time points.
• Microscopic examination assessed the proportion of degenerating spermatozoa, lymphocytes, and phagocytes.

Main Results:

• Significant sperm resorption was observed: approximately 100 x 10^6 by 6 weeks and 426 x 10^6 by 6 months post-vasectomy.
• The vasectomized tract showed a high percentage of degenerating spermatozoa and lymphocytes.
• Very few intraluminal phagocytes were detected, suggesting limited phagocytosis.

Conclusions:

• Spermatozoa are actively resorbed within the male reproductive tract following vasectomy.
• Intraluminal dissolution of spermatozoa (heads and tails) is the predominant mechanism for sperm disposal.
• Phagocytosis plays a minor role in the clearance of spermatozoa after vasectomy in mice.