[Vasodilatory action of FK 409 on bovine retinal arteries--analysis by a microvessel perfusion system].
OBJECTIVE
We investigated the vasodilatory action of FK 409 on bovine retinal arteries using a microvessel perfusion system in vitro.


METHODS
Bovine retinal arteries were obtained from bovine eyes. The arteries, 3 mm long and 110 microns in diameter, were attached to the microvessel perfusion system. The arteries were perfused with Tyrode solution containing 10(-6) M U46619, followed by 10(-6) M U46619 and FK 409 (10(-3) M or 10(-4) M). We also perfused the arteries with carboxy-2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide. The inner diameter of the arteries was measured under a microscope and analyzed by computer.


RESULTS
FK 409 prevented contraction of bovine retinal arteries induced by perfusion of 10(-6) M U46619 when the arteries were perfused with 10(-3) to 10(-4) M FK 409. Addition of 100 microM PTIO, an nitric oxide (NO)-specific extinction agent, into the mixture of U46619 and FK 409 hadan antagonistic effect on the contractive action of FK 409.


CONCLUSIONS
These results suggest that FK 409 has a dilatational effect on bovine retinal arteries and that the dilatational action of FK 409 is possibly produced by NO.
Department of Physiology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan.
Kayo
K
Sugimoto
Tomiko
T
Watanabe
Masaaki
M
Sahara
Toshihiko
T
Ueda
Tadashi
T
Hisamitsu
Ryohei
R
Koide
D000818:Animals; D002417:Cattle; D003497:Cyclic N-Oxides / Q000494:pharmacology; D007093:Imidazoles / Q000494:pharmacology; D066298:In Vitro Techniques; D009574:Nitro Compounds / Q000494:pharmacology*; D010477:Perfusion / Q000379:methods*; D012161:Retinal Artery / Q000187:drug effects*; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000494:pharmacology*
D003497:Cyclic N-Oxides; D007093:Imidazoles; D009574:Nitro Compounds; D014665:Vasodilator Agents; C079391:2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide; C061872:FK 409