The GnRH Agonist Triptorelin Causes Reversible, Focal, and Partial Testicular Atrophy in Rats, Maintaining Sperm...

Area of Science:

• Reproductive endocrinology
• Translational research
• Pediatric endocrinology

Background:

• Pubertal delay is a clinical concern in transgender youth.
• GnRH agonists are used to suppress puberty.
• Understanding reproductive effects is crucial for patient care.

Purpose of the Study:

• To establish a rat model for studying the reproductive effects of GnRH agonist triptorelin in peripubertal transgender girls.
• To assess testicular maturation and fertility in rats treated with triptorelin during key pubertal stages.

Main Methods:

• 30 Sprague Dawley rats were divided into three groups (control, short-term triptorelin, long-term triptorelin) from P30 to P95.
• Triptorelin or vehicle was administered at specific time points (P30, P50, P71).
• Plasma testosterone, testicular histology, and epididymal sperm were analyzed.

Main Results:

• Triptorelin treatment significantly reduced testosterone levels, indicating delayed puberty.
• Testes were smaller in treated rats, with focal atrophy in seminiferous tubules (1-30% parenchyma).
• Despite atrophy, all treated rats maintained mature sperm in the epididymis, preserving fertility.

Conclusions:

• Triptorelin-induced pubertal delay is partially reversible and compatible with spermatogenesis and fertility.
• The GnRH agonist triptorelin may be a viable option before estrogen therapy for transgender girls.
• This rat model provides insights into the reproductive consequences of GnRH agonist use in this population.