Morphometric Analysis of Intracavernosal Smooth Muscle and Intratunical Elastic Fiber in Rat with Erectile Dysfunction

Kim, Jong Il; Park, Nam Cheol

Abstract

PURPOSE: Smooth muscle of the corpus cavernosum and elastic fiber of the tunica albuginea play an important role in erection and the maintenance of the erection. A morphometric analysis of smooth muscle of the corpus cavernosum and elastic fiber of the tunica albuginea was made on a .group of the rats to evaluate the effect of three major causes of impotence - neurogenic, vasculogenic, and endocrinologic - on the structure of corpus cavernosum.
MATERIALS AND METHODS
The male adult Sprague Dawley rats (weight 200 - 250 g) that were included in this study were divided into 4 groups: control group, sham operation (n= 10); group I, bilateral block of major pelvic plexus (n=20); group II, bilateral ligation of hypogastric artery (n=20); group III, bilateral orchiectomy (n=20). Biopsy specimens of the corpus cavernosum and the tunica albuginea were collected at postoperative 4th week. Using a computerized image analyzer (VIDAS, Kontron Electronics, Munich, Germany), morphometric analysis was performed on the immunohistochemical stained specimens using anti-smooth muscle actin to measure percentage of smooth muscle per standard square area and on the Verhoffer stained specimens to determine the number of elastic fiber of the tunica albuginea per high power field (x 400).
RESULTS
The percentage of the intracavernosal smooth muscle was significantly decreased in group I (10,14+-1.22%), group II (10.55+-1.09%), and group III (10.60+-1.21%), in comparison with control group (18.44+1.30%) (p< 0.0001). The number of the intratunical elastic fiber was significantly decreased in group I (38.81+-4.07%), group II (39.11+-1.03%), and group III (37.27+-2.70%), in comparison with control group (79.66+-2.38%) (.p< 0.0001). In group I, II, and III, the reduction rates of elastic fiber were higher than those of smooth muscle, but with no correlation (r=0.03).
CONCLUSION
We conclude from this study that the intracavernosal smooth muscle and the intratunical elastic fiber were quantitatively affected by all three factors including neurogenic, vasculogenic, and endocrinologic.