OBJECTIVETo observe the effects of flutamide (Flu) on the development of testicular germocytes in SD rats, and to establish a rat model for further researches on the maldevelopment of cryptorchidism gonocytes (Go).

METHODSPregnant SD rats were subcutaneously injected with Flu from gestational day (GD) 12 to 21 to establish a model of cryptorchidism. The testes of the newborns were harvested on postnatal day (PD) 1, 10, 20 and 80 for observation of their morphological and histological changes by HE staining and detection of the expression of neural cell adhesion molecules (NCAM) by immunohistochemistry and RT-PCR.

RESULTSFlu induced 43.9% (29/66) of cryptorchidism in the exposed rats. Significant differences were found in the testicular weight and organ coefficient between the Flu and the control groups on PD 20 and 80. Gos remained in the center of seminiferous tubules of the Flu-induced testis on PD 10, and in the center of seminiferous tubules in the cryptorchids' testicular tissues on PD 20 and 80. Immunohistochemistry showed the expression of NCAM on the membrane of the remaining Gos, and RT-PCR revealed significantly up-regulated expression of NCAM mRNA in the Flu-induced testes on PD 10 and 20 as compared with the controls (P < 0.05).

CONCLUSIONA rat model of Flu-induced cryptorchidism with remaining Gos was successfully established, which could be used to study the mechanism and management of the maldevelopment of cryptorchidism gonocytes.