Does prostaglandin E1 therapy modify the intracavernous musculature?

Purpose: Intracavernous injection of prostaglandin E1 in patients with erec tile dysfunction has become widespread. However, to our knowledge long-term side effects on the penile smooth muscles in man have not been documented. We evaluated the histological changes of intracavernous smooth muscle afte r long-term treatment with prostaglandin E1. Materials and Methods: A total of 10 patients with a mean age of 56.5 years (range 46 to 69) underwent biopsy of the corpora before (5) and after (10 in both corpora) prostaglandin E1 treatment. Between 150 and 250 injections during 3 years were performed, and the dosage varied from 5 to 20 mu g. On ly 1 patient injected prostaglandin E1 on both sides. Staining with hematox ylin and eosin, and immunohistochemical staining with actin anti-actin of i ntracavernous smooth muscle and its quantification with computerized image analysis were performed. Results: No histological difference was observed with classic staining. A r eduction was noted in the percentage of intracavernous smooth muscle after treatment in 2 of 5 patients on the side of injection (before 35% and 41%, and after 19% and 30%, respectively) but there was no difference with the o ther corpus cavernosum No difference was observed in the percentage of intr acavernous smooth muscle between both corpora in the 5 patients with biopsi es performed only after treatment. Conclusions: Prostaglandin E1 does not seem to alter intracavernous structu res.