Abstract
Reasons for performing study: Cryptorchidism affects 2-8% of male horses and the affected testis undergoes a disruption of normal spermatogenesis. The underlying molecular changes are poorly understood in the cryptorchid equine testis. Objectives: Compare the expression of anti-Müllerian hormone (AMH), anti-Müllerian hormone receptor (AMHR2), androgen receptor (AR), cyclin kinase inhibitor (CDKN1B), connexin 43 (Cx43), 3β hydroxysteroid dehydrogenase/Δ5-Δ4- isomerase (3βHSD), P450c17 hydroxylase/lyase (P450c17) and cytochrome P450 aromatase (P450arom) in the undescended testis of cryptorchid stallions with that of normal stallions. Methods: Undescended, abdominal testes from four cryptorchid stallions between 2 and 3 years of age were collected during routine castrations along with normally descended testes from normal stallions between 2 and 3 years of age (n = 7). Samples were analysed by immunohistochemistry and quantitative real-time PCR. Results: Cryptorchid testes had increased AMH and AMHR2 immunolabelling when compared with normal testes, which indicates failure of maturation of Sertoli cells and/or lack of testosterone suppression. Failure of Sertoli cell maturation in the cryptorchid testis may also be attributed to AR abnormalities and/or a consequence of lack of testosterone suppression due to decreased 3βHSD. Cyclin-dependent kinase (CDKN1B) was not expressed in Sertoli cells of cryptorchid testes suggesting that Sertoli cells are still proliferating, which is also a characteristic of the immature testis. In addition, Cx43 expression is decreased in the cryptorchid testis, indicating a disruption in intercellular communication. Conclusions: Undescended testes of cryptorchid horses present characteristics of immaturity suggesting that the failure of Sertoli cell maturation may be a consequence of cryptorchidism. Potential relevance: This study provides a better understanding of the effect of cryptorchidism on testicular function in stallions.
Original language | English (US) |
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Pages (from-to) | 538-545 |
Number of pages | 8 |
Journal | Equine Veterinary Journal |
Volume | 45 |
Issue number | 5 |
DOIs | |
State | Published - Sep 2013 |
Keywords
- Anti-Müllerian hormone
- Cryptorchid
- Horse
- Sertoli cell
- Steroidogenesis
- Testis
ASJC Scopus subject areas
- Equine