[The effects of sildenafil citrate on the isolated rat aorta: comparative in vitro study].
OBJECTIVE
Sildenafil, an inhibitor of cGMP-specific phosphodiesterase 5 (PDE5), is currently being used as oral therapy for penile erectile dysfunction. The aim of this study was to investigate the relaxing effect of sildenafil on vascular tissue and compare it with the known vasodilatator agents, sodium nitroprusside and acetylcholine.


METHODS
Rat thoracic aorta samples were cut into rings, mounted on steel hooks, and immersed in aerated Krebs solution maintained at 37 degree C. Isometric responses were recorded by strain gauge transducers connected to a polygraph. Graded relaxations were induced using increasing concentrations of acetylcholine sodium nitroprusside and sildenafil.


RESULTS
The agents all does-dependently relaxed rat aorta strips. The relaxing potential of sildenafil was found to be similar to sodium nitroprusside, but higher than acetylcholine.


CONCLUSIONS
In the absence of regulatory mechanisms, sildenafil citrate has noticeable vasodilatatory effect in vitro.
Yüzüncü Yil Universitesi Tip Fakültesi Farmakoloji, Kardiyoloji. hanefiozbek@hotmail.com
H
H
Ozbek
N
N
Güler
S
S
Aydin
B
B
Eryonucu
M
M
Bilge
D000109:Acetylcholine / Q000008:administration & dosage / Q000494:pharmacology; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D008297:Male; D009599:Nitroprusside / Q000008:administration & dosage / Q000494:pharmacology; D010879:Piperazines / Q000008:administration & dosage / Q000494:pharmacology*; D011687:Purines; D051381:Rats; D017207:Rats, Sprague-Dawley; D000068677:Sildenafil Citrate; D013450:Sulfones; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000494:pharmacology*
D010879:Piperazines; D011687:Purines; D013450:Sulfones; D014665:Vasodilator Agents; D009599:Nitroprusside; D000068677:Sildenafil Citrate; D000109:Acetylcholine