[Effects of cilostazol, a cyclic AMP phosphodiesterase inhibitor, on pulmonary vascular tone].
We examined the effect of Cilostazol, a cyclic AMP phosphodiesterase inhibitor, rat isolated pulmonary arterial ring tone. Cilostazol dilated pulmonary arterial rings pre-contracted with 10(-6) M phenylephrine in a dose-dependent manner (ED50 3.00 x 10(-6) M). This vasodilatory effect of Cilostazol was not affected by pretreatment with meclofenamate (10(-5) M), mechanical endothelium denudation, methylene blue (10(-5) M) or nitro-L-arginine (2 x 10(-4) M). The vasodilatory effect of Cilostazol on rat thoracic aortic rings was stronger than that on rat pulmonary arterial ring (ED50 1.89 x 10(-6) M). Cilostazol (10(-6) M-10(-4) M) inhibited hypoxic contraction of rat pulmonary rings in a dose-dependent manner. Our experimental data indicated that Cilostazol caused vasodilation regardless of vascular endothelium function and inhibited hypoxic contraction due to inhibition of cyclic AMP phosphodiesterase.
Shigemori
K
K
Third Department of Internal Medicine, Fukui Medical School, Japan.
Ishizaki
T
T
Takahashi
H
H
Sasaki
F
F
Ameshima
S
S
Ohnishi
T
T
Sakai
T
T
Nakai
T
T
Miyabo
S
S
D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000037:antagonists & inhibitors*; D000818:Animals; D000077407:Cilostazol; D008297:Male; D011651:Pulmonary Artery / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013268:Stimulation, Chemical; D013777:Tetrazoles / Q000494:pharmacology*; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000494:pharmacology*
D013777:Tetrazoles; D014665:Vasodilator Agents; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D000077407:Cilostazol