DA-8159, a new PDE5 Inhibitor, Induces Penile Erection in Conscious and Acute Spinal Cord Injured Rabbits

• Published in: European urology 2003-06, Vol.43 (6), p.689-695
• Main Authors: Kang, Kyung Koo, Ahn, Gook Jun, Ahn, Byoung Ok, Yoo, M., Kim, Won Bae
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; DA-8159; Genital system. Reproduction; Medical sciences; Penile erection; Pharmacology. Drug treatments; Phosphodiesterase inhibitor; Rabbit; Spinal cord injury
• ISSN: 0302-2838; 1873-7560
• DOI: 10.1016/S0302-2838(03)00153-2

Objectives: DA-8159 is a pyrazolopyrimidinone derivative showing potent and selective phosphodiesterase 5 (PDE5) inhibition. In the previous study, DA-8159 induced a dose-dependent increase in the intracavernous pressure (ICP) in anaesthetized dogs. The aim of this study was to investigate the effects of DA-8159 on penile erection in conscious and acute spinal cord injured (ASCI) rabbits. Methods: DA-8159 was given orally (0.3 to 10 mg/kg) to normal rabbits and ASCI rabbits with a surgical transection of the spinal cord at the L2–L4 lumbar vertebra or ischemic-reperfusion. The erection was evaluated in a time-course manner by measuring the length of the uncovered penile mucosa in the absence or presence of intravenous sodium nitroprusside (SNP), a nitric oxide (NO) donor. Results: DA-8159 induced a dose-dependent penile erection in both the conscious and ASCI rabbits. The efficacy of DA-8159 was potentiated and the effective doses were significantly decreased by an intravenous injection of SNP. Potentiation of the effect by a nitric oxide donor implies that DA-8159 can enhance the erectile activity during sexual arousal. Conclusion: These results demonstrate that DA-8159 may be a useful treatment option for erectile dysfunction in patients with or without a spinal cord injury, but further evaluation of the effects of DA-8159 on humans must be performed.