As to the effect of PGE-1 on the tunica. Studies indicate that PGE-1 hinders collagen production and can unlink collagen fibers making the tunica easier to stretch.
This information seems to suggest that penile oxygen levels dictate a balance between PGE-1 and TGF-β1. Low oxygen levels trigger collagen production and fibrosis. PGE-1 seems to have the reverse effect. That's if I am reading these articles correctly. If this is the case, PGE-1 would likely be superior to other vasodilators (Papervine, phenotolamine, etc. )
Quote:
Revascularization of Myocardial Scar Tissue Following Prostaglandin E1-Therapy in Patients with Ischemic Heart Disease
PGE-1-treated patients had significantly more CD34- and VEGF-positive cells in infarcted areas, and showed a significant reduction in collagen content as compared with the non-PGE-1 group
http://www.sciencedirect.com/scienc...f021b945feb1b3f
Quote:
Fibrosis of corpus cavernosum in animals following cavernous nerve ablation
PGE1 suppresses the induction of collagen sythesis by transforming grouth factor-beta 1 in human corpus cavernosum smooth muscle. J Urol 1995; 153: 826-34.
http://www.asiaandro.com/1008-682X/6/111.htm
Quote:
Penile Rehabilitation After Radical Prostatectomy: Important Therapy or Wishful Thinking?
Together, these studies suggest that the collagen content in the corpus cavernosum is regulated by oxygen tension through the increased or decreased expression of TGF-β1 and PGE1. During low oxygen tension, increased expression of TGF-β1 activates a molecular cascade to increase collagen and other connective tissue synthesis. During high oxygen tension, on the other hand, increased expression of PGE1 activates an alternate cascade to decrease collagen synthesis. To date, the data are insufficient to confirm that this delicate balance of TGF-β1 and PGE1 expression actually dictates the varying amounts of smooth muscle and connective tissue content within the corpus cavernosum at physiologic oxygen tensions.
http://www.pubmedcentral.nih.gov/ar...i?artid=1751036