Effect of androgen deprivation on penile ultrastructure.
OBJECTIVE
To investigate the ultrastructural changes of penile corpus cavernosum and tunica albuginea in rats treated with castration or finasteride.


METHODS
Eighteen male Sprague-Dawley rats of nine weeks old were randomly divided into three groups with 6 rats each. Group A served as the control, Group B was castrated and Group C, treated with finasteride. Four weeks later, rats were anesthetized and blood samples obtained for the determination of serum testosterone (T) and dihydrotestosterone (DHT) levels; penile tissues were taken for scanning electron microscopy.


RESULTS
The T, free T and DHT levels in Group B and the DHT level in Group C were significantly lower than those in Group A (P<0.05). The tunica albuginea was significantly thinner in Group B than that in Group A (P<0.05), but there was no significant difference between Group C and Group A (P>0.05). Elastic fibers in the tunica albuginea of Group A were very rich and arranged regularly and undulatedly, but in Group B, most of the elastic fibers were replaced by collagenous fibers. In Group C, the tunica albuginea was mainly composed of thick and irregular-arranged collagenous fibers. In Group A, there were abundant smooth muscle fibers in the trabeculae of corpus cavernosum, but they were much less in Group C and scarce or even disappeared in Group B. In Groups B and C, the diminished/disappeared smooth muscle fibers were replaced by irregularly arranged collagenous fibers.


CONCLUSIONS
In rats, androgen is essential for maintaining the normal structure of penile tunica albuginea and corpus cavernosum.
Shen
Zhou-Jun
ZJ
Department of Urology, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, China. shenzhj@mail.hz.zj.cn
Zhou
Xie-Lai
XL
Lu
Ying-Li
YL
Chen
Zhao-Dian
ZD
D000818:Animals; D013196:Dihydrotestosterone / Q000097:blood; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018120:Finasteride / Q000494:pharmacology; D008297:Male; D008855:Microscopy, Electron, Scanning; D009919:Orchiectomy; D010413:Penis / Q000473:pathology* / Q000648:ultrastructure*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013739:Testosterone / Q000097:blood / Q000172:deficiency*
D004791:Enzyme Inhibitors; D013196:Dihydrotestosterone; D013739:Testosterone; D018120:Finasteride