The effect of DA-8159 on corpus cavernosal smooth muscle relaxation and penile erection in diabetic rabbits.

Abstract

A previous study showed that DA-8159, a potent type 5 phosphodiesterase inhibitor, enhanced the relaxation of the smooth muscles in the normal rabbit corpus cavernosum. In this study, we investigated the in vitro effects of DA-8159 on cavernosal smooth muscle relaxation and the in vivo erectogenic potential in diabetic rabbits, since erectile dysfunction is a well-known sequela of diabetes mellitus. Diabetes mellitus was induced in male New Zealand White rabbits with alloxan monohydrate. Cavernosal strips from age-matched control and 8-week diabetic animals were mounted in organ baths. The relaxation responses to sodium nitroprusside (10(-9)--10(-5) M), a nitric oxide donor, were assessed in the presence or absence of DA-8159 (10(-9)--10(-6) M). For the penile erection test, DA-8159 was given orally (1-10 mg/kg) to diabetic rabbits and the length of the uncovered penile shaft was measured in a time-course manner in the presence or absence of intravenous sodium nitroprusside. The sodium nitroprusside-stimulated relaxations were significantly impaired in the corpus cavernosum from the diabetic group (IC(50)=1.07 x 10(-6) M following 8 weeks of diabetes mellitus; compared with 0.48 x 10(-6) M for age-matched controls). DA-8159 significantly and dose-dependently enhanced the sodium nitroprusside-stimulated relaxation in the diabetic groups. In addition, DA-8159 induced a dose-dependent penile erection in diabetic rabbits, which was potentiated by intravenous sodium nitroprusside. These results suggest that DA-8159 is an effective treatment for diabetic erectile dysfunction but further evaluation of the efficacy on human needs to be performed.

• Authors: Kyung Koo Kang, Seul Min Choi, Gook Jun Ahn, Jong Won Kwon, Won Bae Kim
• Journal: Urological research (Urol Res) Vol. 32 Issue 2 Pg. 107-11 (May 2004) ISSN: 0300-5623 [Print] Germany
• PMID: 15024530 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Blood Glucose
• Phosphodiesterase Inhibitors
• Pyrimidines
• Sulfonamides
• Vasoconstrictor Agents
• Vasodilator Agents
• Nitroprusside
• Phenylephrine
• udenafil

Topics

• Animals
• Area Under Curve
• Blood Glucose (analysis)
• Body Weight
• Diabetes Mellitus, Experimental (metabolism, physiopathology)
• Dose-Response Relationship, Drug
• Male
• Muscle Relaxation (drug effects)
• Muscle, Smooth (drug effects, physiopathology)
• Nitroprusside (pharmacology)
• Penile Erection (drug effects)
• Penis (enzymology, metabolism, physiology)
• Phenylephrine (pharmacology)
• Phosphodiesterase Inhibitors (pharmacology)
• Pyrimidines (pharmacology)
• Rabbits
• Sulfonamides
• Vasoconstrictor Agents (pharmacology)
• Vasodilator Agents (pharmacology)