Effect of epidermal growth factor on spermatogenesis in the cryptorchid rat.
OBJECTIVE
Epidermal growth factor (EGF) is secreted mainly from the submandibular glands. Submandibular gland ablation causes a marked decrease in male fertility, which suggests that EGF influences spermatogenesis. We investigated the effect of EGF in combination with orchiopexy on cryptorchid rat testes in which tubular deterioration had become partially irreversible.


METHODS
Unilaterally cryptorchid rats were obtained by daily administration of 7.5 mg flutamide (Nihonkayaku, Tokyo, Japan), an androgen receptor antagonist, to pregnant rats. At age 10 weeks the unilaterally cryptorchid rats underwent orchiopexy with or without EGF administered into the cryptorchid testis. EGF solution (10 microg/ml) was delivered into the seminiferous tubules by retrograde perfusion through the rete testis. At 14 days testicular recovery was assessed based on the maturity of spermatogenesis using a modified Johnsen score and from the number of apoptotic germ cells per seminiferous tubule.


RESULTS
Mean Johnsen score +/- SEM was significantly higher in the orchiopexy with EGF than in the orchiopexy without EGF group (7.85 +/- 0.12 vs 7.12 +/- 0.13, p <0.001). The number of apoptotic germ cells tended to be smaller in the orchiopexy with EGF group than in the orchiopexy without EGF group (0.16 +/- 0.05 vs 0.28 +/- 0.08).


CONCLUSIONS
Although orchiopexy for cryptorchidism partly improved spermatogenesis, recovery was limited. EGF administered in combination with orchiopexy was more effective for spermatogenesis than orchiopexy alone. This may be applicable in patients with cryptorchidism.
Kurokawa
Satoshi
S
Department of Nephro-urology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Nagoya 467-8601, Japan.
Kojima
Yoshiyuki
Y
Mizuno
Kentaro
K
Nakane
Akihiro
A
Hayashi
Yutaro
Y
Kohri
Kenjiro
K
D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis / Q000187:drug effects; D015415:Biomarkers / Q000097:blood; D003131:Combined Modality Therapy; D003456:Cryptorchidism / Q000188:drug therapy / Q000503:physiopathology* / Q000601:surgery / Q000628:therapy*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004815:Epidermal Growth Factor / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D005260:Female; D005854:Germ Cells / Q000187:drug effects; D020287:In Situ Nick-End Labeling; D008297:Male; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D012671:Seminiferous Tubules / Q000166:cytology / Q000378:metabolism / Q000503:physiopathology; D013091:Spermatogenesis / Q000187:drug effects; D013737:Testis / Q000601:surgery*
D015415:Biomarkers; D004815:Epidermal Growth Factor