Timing of prepubertal androgen administration may have different effects on future fertility as well as penile size in normal male rats.
OBJECTIVE
To investigate the effects of androgen administration at different periods of prepubertal life on penile size and potential fertility in hormonally normal rats.


METHODS
Eighty Sprague-Dawley rats were divided into 4 groups; group 1 received weekly injections of testosterone enanthate (8 mg/100 g) at 1-3 weeks group 2 at 3-5 weeks, group 3 at 1-5 weeks, and group 4 was control (n = 20 each). Animals were killed at age 60 days. Penile length, penile, testicular, and epididymal weight, testicular fertility index, serum follicular stimulating hormone, luteinizing hormone, and testosterone levels were measured and quantitative real time polymerase chain reaction of penile androgen receptor messenger ribonucleic acids was performed.


RESULTS
Penile length in the 3-5-week injection group was significantly longer than controls (41.18 vs 39.13 mm, P = .011), and it was smaller than controls in the 1-3 week injection group (37.24 vs 39.13 mm, P = .020). The penile wet weight showed a similar pattern to stretched penile length; however, statistical significance was not found. Testicular weight was significantly less in the testosterone injection group than controls (1.79, 2.16, 2.24, and 2.78 g in groups 1-4, respectively) as well as the epididymal weight (0.48, 0.42, 0.59, and 0.69 in groups 1-4, respectively). The mean tubular diameter and germ cell count were significantly reduced in the testosterone treated group. Total penile androgen receptor messenger ribonucleic acid level was significantly lower in group 3 as compared with controls.


CONCLUSIONS
Testosterone administered during early prepubertal life resulted in smaller penis than controls, as well as having an adverse effect on testicular development which can jeopardize potential fertility.
Lee
Hyeyoung
H
Department of Urology and the Urological Science Institute, Yonsei University College of Medicine, Seoul, Korea.
Jin
Mei Hua
MH
Kang
Hyo Jin
HJ
Hong
Chang Hee
CH
Bang
Woo Jin
WJ
Park
Kyung Ki
KK
Han
Sang Won
SW
D000367:Age Factors; D000728:Androgens / Q000008:administration & dosage*; D000818:Animals; D005298:Fertility / Q000187:drug effects*; D008297:Male; D010413:Penis / Q000033:anatomy & histology* / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012741:Sexual Maturation; D013739:Testosterone / Q000008:administration & dosage / Q000031:analogs & derivatives*
D000728:Androgens; D013739:Testosterone; C004648:testosterone enanthate