ANALYTICAL CLINICAL STUDIES
Expression of anti-Müllerian hormone, CDKN1B, connexin 43, androgen receptor and steroidogenic enzymes in the equine cryptorchid testis
Article first published online: 7 JAN 2013
© 2012 EVJ Ltd
Equine Veterinary Journal
Volume 45, Issue 5, pages 538–545, September 2013
How to Cite
Almeida, J., Conley, A. J. and Ball, B. A. (2013), Expression of anti-Müllerian hormone, CDKN1B, connexin 43, androgen receptor and steroidogenic enzymes in the equine cryptorchid testis. Equine Veterinary Journal, 45: 538–545. doi: 10.1111/evj.12013
- Issue published online: 2 AUG 2013
- Article first published online: 7 JAN 2013
- Accepted manuscript online: 28 OCT 2012 08:25PM EST
- Manuscript Accepted: 19 OCT 2012
- Manuscript Received: 2 MAR 2012
- John P. Hughes Endowment
- UC Davis Center for Equine Health
- CAPES and Fulbright
- Sertoli cell;
- anti-Müllerian hormone
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.
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.
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.
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.
Undescended testes of cryptorchid horses present characteristics of immaturity suggesting that the failure of Sertoli cell maturation may be a consequence of cryptorchidism.
This study provides a better understanding of the effect of cryptorchidism on testicular function in stallions.