title: Development and descent of the testis in relation to cryptorchidism.
abstract: The testis descends in two phases. Animal studies suggest, that the transabdominal descent of the testis depends on the insulin-like hormone 3 (INSL3). Androgens are important in the inguinoscrotal testicular descent in animals and humans. In general, the cause of cryptorchidism is unknown and the aetiology is possibly multifactorial. Histological changes in cryptorchid testes demonstrate disturbed development.
  
  
  CONCLUSIONS
  Since testicular descent is regulated by testis-derived hormones, cryptorchidism may reflect a functional defect of the testis.
authors.affiliation: Department of Physiology, University of Turku, Kiinamyllynkatu 10, FIN-20520 Turku, Finland.
authors.forename: Helena E
authors.initials: HE
authors.lastname: Virtanen
authors.forename: Dina
authors.initials: D
authors.lastname: Cortes
authors.forename: Ewa
authors.initials: E
authors.lastname: Rajpert-De Meyts
authors.forename: E Martin
authors.initials: EM
authors.lastname: Ritzén
authors.forename: Agneta
authors.initials: A
authors.lastname: Nordenskjöld
authors.forename: Niels E
authors.initials: NE
authors.lastname: Skakkebaek
authors.forename: Jorma
authors.initials: J
authors.lastname: Toppari
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D002648:Child; D003456:Cryptorchidism / Q000196:embryology* / Q000235:genetics / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D007223:Infant; D007328:Insulin / Q000502:physiology; D007985:Leydig Cells / Q000166:cytology / Q000502:physiology; D008297:Male; D023421:Models, Animal; D011506:Proteins / Q000502:physiology; D013737:Testis / Q000196:embryology*
chemical_list: D007328:Insulin; C084797:Leydig insulin-like protein; D011506:Proteins