Development and descent of the testis in relation to cryptorchidism.
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.
Virtanen
Helena E
HE
Department of Physiology, University of Turku, Kiinamyllynkatu 10, FIN-20520 Turku, Finland.
Cortes
Dina
D
Rajpert-De Meyts
Ewa
E
Ritzén
E Martin
EM
Nordenskjöld
Agneta
A
Skakkebaek
Niels E
NE
Toppari
Jorma
J
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*
D007328:Insulin; C084797:Leydig insulin-like protein; D011506:Proteins