Objective: To investigate the pathological changes of tunica albuginea in erectile dysfunction (ED), the role of tunica albuginea in penis erection, and the therapeutic effect of phosphodiesterase-5 inhibitor (PDE5I) on ED.
Methods: Thirty 8-week-old male Sprague-Dawley rats were randomly divided into 3 equal groups: (1) control group fed with normal diet for 16 weeks, (2) high-fat group fed with the diet containing 2% cholesterol and 10% pork fat, and (3) Tadalafil group fed with high-fat diet for 16 weeks and undergoing gastric perfusion of Tadalafil 2 mg/kg daily since the 13th week for 4 weeks. Sixteen weeks later, intracavernous pressure and mean arterial pressure were measured, and the ratio of maximal intracavernous pressure to mean arterial pressure (ICP/MAP) was calculated blood samples were collected. Blood samples were collected from the abdominal aorta to undergo lipid profile test. Then penis was cut. Victoria blue/ponceau red staining and color image analysis were used to observe the content of elastic fibers in the tunica albuginea.
Results: The ICP/MAP of the high-fat group was 0.49 +/- 0.05, significantly lower than that of the control group (0.82 +/- 0.06, P < 0.01). The ICP/MAP of the Tadalafil group was 0.60 +/- 0.02, significantly higher than that of the high-fat group (P < 0.05). The content of elastic fibers in tunica albuginea of the high-fat group was 468 +/- 152, significantly lower than that of the the control group (3292 +/- 1123, P < 0.01). The content of elastic fibers in tunica albuginea of the Tadalafil group was 2062 +/- 560, significantly higher than that of the high-fat group (P < 0.05).
Conclusion: High fat diet may lead to ED and reduction of elastic fibers in tunica albuginea, and PDE-5I reverses such pathological changes.