title: Effects of androgen on the expression of vascular endothelial growth factor in the penile corpus cavernosum.
abstract: OBJECTIVE
  To investigate the effect of orchiectomy and androgen replacement on the expression of vascular endothelial growth factor (VEGF) in rat penile tissue.
  
  
  METHODS
  Adult male Sprague-Dawley rats (12 weeks old) were left intact (control) or surgically castrated. Orchiectomized rats were left untreated or received testosterone propionate (TP) for 7 days, beginning 1 or 2 weeks after castration. Erectile function was assessed by measuring intracavernosal pressure in response to cavernous nerve stimulation, and the expression of VEGF protein and mRNA was determined by immunohistochemistry, Western blot analysis, and reverse transcriptase-polymerase chain reaction. Serum testosterone values were measured in each animal by radioimmunoassay.
  
  
  RESULTS
  Serum androgen levels decreased significantly in castrated animals, whereas TP injection normalized the serum levels of testosterone. Intracavernosal pressure was significantly decreased in untreated castrated rats (31.3 ± 15.7% at 2 weeks postcastration; 18.6 ± 4.6% at 3 weeks postcastration) compared with intact controls (58.0 ± 11.4% and 58.9 ± 8.2%, respectively). Erectile function was normalized in androgen-replaced rats, irrespective of treatment was initiation 1 or 2 weeks after orchiectomy. The expression of VEGF protein and mRNA was decreased in the corpus cavernosum of castrated animals compared with controls, whereas androgen replacement normalized the expression of VEGF. These results were consistently observed by all 3 methods of assessment.
  
  
  CONCLUSIONS
  These data suggest that androgen regulates the expression of VEGF in rat penile corpus cavernosum and confirms the importance of androgens in the maintenance of erectile function.
authors: Department of Urology, Chonnam National University Medical School, Gwangju, Korea.
authors: Eu Chang
authors: EC
authors: Hwang
authors: Kyung Jin
authors: KJ
authors: Oh
authors: Seung Il
authors: SI
authors: Jung
authors: Noel N
authors: NN
authors: Kim
authors: Kyu Youn
authors: KY
authors: Ahn
authors: Kwangsung
authors: K
authors: Park
mesh_terms: D000728:Androgens / Q000097:blood / Q000378:metabolism*; D000818:Animals; D005786:Gene Expression Regulation; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D009919:Orchiectomy / Q000379:methods; D010410:Penile Erection; D010413:Penis / Q000378:metabolism* / Q000473:pathology*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013739:Testosterone / Q000097:blood; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis*
chemical_list: D000728:Androgens; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; D013739:Testosterone