Chronic vardenafil treatment improves erectile function via structural maintenance of penile corpora cavernosa in rats with acute arteriogenic erectile dysfunction.

Abstract

INTRODUCTION:

Chronic phosphodiesterase type 5 inhibitor treatment may be useful in reversing erectile dysfunction (ED). However, the mechanisms of this improvement remain unknown.

AIM:

The aim of this article was to determine the mechanisms of the improvement by chronic vardenafil treatment for acute arteriogenic ED in rats.

METHODS:

Eight-week-old male Wistar-ST rats were divided into four groups: sham-operated rats (Control group) and rats with acute arteriogenic ED induced by ligating bilateral internal iliac arteries (Ligation group), subsequently treated with low-dose (0.4 mg/kg/day; VL group) or high-dose (4.0 mg/kg/day; VH group) vardenafil for 20 days from 1 week after ligature.

MAIN OUTCOME MEASURES:

Erectile function was assessed based on changes of intracavernous pressure (ICP) followed by electrostimulation of the cavernous nerves and was evaluated by the area under the curve of ICP/area under the curve of mean arterial pressure (area of ICP/MAP). Transforming growth factor (TGF)-β(1), vascular endothelial growth factor-A, endothelial nitric oxide synthase (eNOS), inducible NOS, and neuronal NOS mRNA expression levels in penile corpus cavernosum were determined by real-time PCR. Western blotting for TGF-β(1) protein levels and Masson trichrome staining of penile tissues were performed in each at group 4 weeks after surgery.

RESULTS:

In the VH group, area of ICP/MAP was significantly improved when compared with the Ligation group (P < 0.01). The smooth muscle (SM)/collagen ratio in the VH group was significantly higher than in the Ligation group (P < 0.05), and was comparable with that in the Control group. TGF-β(1) mRNA and protein levels in the VH group were significantly lower when compared with the Ligation group (P < 0.05).

CONCLUSIONS:

Chronic vardenafil administration ameliorates impairment of penile hemodynamics and maintains normal SM to collagen ratio in cavernous tissues after acute arterial injury in rats.

• Authors: Yuji Hotta, Mayuko Hattori, Tomoya Kataoka, Risa Ohno, Mayumi Mikumo, Yasuhiro Maeda, Kazunori Kimura
• Journal: The journal of sexual medicine (J Sex Med) Vol. 8 Issue 3 Pg. 705-11 (Mar 2011) ISSN: 1743-6109 [Electronic] Netherlands
• PMID: 21143425 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2010 International Society for Sexual Medicine.

Chemical References

• Imidazoles
• Phosphodiesterase 5 Inhibitors
• Piperazines
• Sulfones
• Triazines
• Vardenafil Dihydrochloride
• Nitric Oxide Synthase Type II
• Nos2 protein, rat

Topics

• Animals
• Blotting, Western
• Disease Models, Animal
• Imidazoles (administration & dosage, pharmacology, therapeutic use)
• Impotence, Vasculogenic (drug therapy)
• Male
• Nitric Oxide Synthase Type II (metabolism)
• Penile Erection (drug effects)
• Penis (blood supply, drug effects)
• Phosphodiesterase 5 Inhibitors (pharmacology, therapeutic use)
• Piperazines (administration & dosage, pharmacology, therapeutic use)
• Rats
• Rats, Wistar
• Reverse Transcriptase Polymerase Chain Reaction
• Sulfones (administration & dosage, pharmacology, therapeutic use)
• Triazines (administration & dosage, pharmacology, therapeutic use)
• Vardenafil Dihydrochloride