Recovery of spermatogenesis by high dose gonadotropin-releasing hormone analogue treatment in rat cryptorchid testis after orchiopexy.
OBJECTIVE
Cryptorchidism is an adverse condition of spermatogenesis in many mammals. Surgical cryptorchidism in rats lasting more than a few weeks is so detrimental that spermatogenesis cannot be completely recovered even after orchiopexy. We evaluated the efficacy of the high dose gonadotropin-releasing hormone (Gn-RH) agonist leuprorelin acetate on damaged spermatogenesis in rat cryptorchid testes.


METHODS
Male Fisher rats were divided into 2 groups of 6 each and bilateral cryptorchidism was artificially produced. Five weeks later all rats underwent bilateral orchiopexy. One group served as the control, while the other received Gn-RH agonist injections at orchiopexy and 4 weeks later. The animals were sacrificed 15 weeks after orchiopexy. The weight of the body, testis and epididymis was measured and the histology of spermatogenesis was examined. For statistical analysis the Student t test was applied.


RESULTS
Testes in the Gn-RH group rats showed significant recovery of spermatogenesis up to complete spermatozoa formation, while those in control rats remained almost degenerated. The mean incidence of seminiferous tubules with recovered spermatogenesis plus or minus standard deviation was significantly higher in the Gn-RH than in the control group (87.8% +/- 6.0% versus 12.5% +/- 7.7%, p <0.001).


CONCLUSIONS
Administering the high dose Gn-RH agonist leuprorelin acetate after orchiopexy greatly enhanced the recovery of spermatogenesis in rats. This finding is in accordance with other recent reports that treatment with Gn-RH analogues promotes the regeneration of once damaged spermatogenesis. On the other hand, these findings may cause one to question supplementation therapy now used in regular practice to boys with cryptorchidism.
Department of Urology, Yokohama City University School of Medicine, Kanazawa-ku, Yokohama, Japan.
Koichi
K
Udagawa
Mitsumasa
M
Takeda
Masahiko
M
Hosaka
Yoshinobu
Y
Kubota
Takehiko
T
Ogawa
D000818:Animals; D003456:Cryptorchidism / Q000503:physiopathology / Q000601:surgery*; D004822:Epididymis / Q000473:pathology; D005854:Germ Cells / Q000473:pathology; D016729:Leuprolide / Q000008:administration & dosage*; D008297:Male; D009929:Organ Size; D051381:Rats; D011916:Rats, Inbred F344; D012671:Seminiferous Tubules / Q000473:pathology; D013091:Spermatogenesis / Q000187:drug effects*; D013737:Testis / Q000473:pathology / Q000601:surgery*
D016729:Leuprolide