The effect of hyperthermia on the mouse testis

Area of Science:

• Reproductive Biology
• Toxicology
• Biophysics

Background:

• Spermatogenesis is a complex process sensitive to environmental factors.
• Hyperthermia, or elevated temperature, is being explored for cancer treatment.
• The impact of localized testicular hyperthermia on spermatogenesis requires detailed investigation.

Purpose of the Study:

• To assess the effects of controlled radiofrequency-induced hyperthermia on different stages of spermatogenesis in mice.
• To determine the threshold for testicular damage and recovery following heat exposure.
• To evaluate the potential risks of testicular hyperthermia for fertility and inform clinical applications.

Main Methods:

• CBA mice testes were subjected to radiofrequency heating to a target temperature of 43°C for 30 minutes, with temperature monitored by thermocouple.
• Testis weight, sperm head counts, and late spermatid populations were evaluated at 14, 28, and 35 days post-treatment.
• Tubule repopulation and morphology were assessed 35 days after heating to categorize treatment outcomes.

Main Results:

• Testis weight decreased to 65% of control at 14 days, recovering to 88% by 28 days.
• Sperm heads and late spermatids reduced to 33% at 14 days, increasing to 88% by day 28.
• Heating to 43°C caused cell depletion and tubule shrinkage, with only 64% of tubules showing normal repopulation by day 35.

Conclusions:

• A 30-minute exposure to 43°C significantly disrupts spermatogenesis and impairs testicular stem cells in mice.
• Incomplete tubule repopulation suggests long-term damage, highlighting risks to fertility.
• Clinicians should exercise caution when considering hyperthermia for testicular tumors due to potential adverse effects on sperm production.