title: Expression of anti-Müllerian hormone, CDKN1B, connexin 43, androgen receptor and steroidogenic enzymes in the equine cryptorchid testis.
abstract: BACKGROUND
  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.
  
  
  OBJECTIVE
  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/Δ(5) -Δ(4) - 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.
  
  
  CONCLUSIONS
  This study provides a better understanding of the effect of cryptorchidism on testicular function in stallions.
authors.affiliation: Universidade de Fortaleza, CE, Brazil.
authors.forename: J
authors.initials: J
authors.lastname: Almeida
authors.forename: A J
authors.initials: AJ
authors.lastname: Conley
authors.forename: B A
authors.initials: BA
authors.lastname: Ball
mesh_terms: D000818:Animals; D054304:Anti-Mullerian Hormone / Q000235:genetics / Q000378:metabolism*; D018031:Connexin 43 / Q000235:genetics / Q000378:metabolism*; D003456:Cryptorchidism / Q000097:blood / Q000378:metabolism / Q000662:veterinary*; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology; D006734:Horse Diseases / Q000378:metabolism*; D006736:Horses; D008297:Male; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011944:Receptors, Androgen / Q000235:genetics / Q000378:metabolism*; D013256:Steroids / Q000378:metabolism; D013737:Testis / Q000378:metabolism
chemical_list: D018031:Connexin 43; D012333:RNA, Messenger; D011944:Receptors, Androgen; D013256:Steroids; D050760:Cyclin-Dependent Kinase Inhibitor p27; D054304:Anti-Mullerian Hormone
keywords: Sertoli cell; anti-Müllerian hormone; cryptorchid; horse; steroidogenesis; testis