Vasodilator effects of ibudilast on retinal blood vessels in anesthetized rats.
Ibudilast (3-isobutyryl-2-isopropylpyrazolo[1,5-alpha]pyridine) is clinically used as a cerebral vasodilator in Japan. However, the effects of ibudilast on retinal blood vessels have not been fully examined. The aim of this study, therefore, was to examine the effects of ibudilast on retinal blood vessels in rats in vivo. Male Wistar rats (8 to 10 weeks old) were anesthetized with thiobutabarbital (120 mg/kg, intraperitoneally (i.p.)). Retinal vascular images were captured with a fundus camera system for small animals, and the diameter of retinal blood vessels was measured. Ibudilast (0.1 and 1 mg/kg, intravenously (i.v.)) elicited a sustained increase in the diameter of retinal blood vessels and heart rate without altering systemic blood pressure. The effects of ibudilast were significantly reduced by treatment with the nonselective cyclooxygenase inhibitor indomethacin (5 mg/kg, i.p.). These results suggest that ibudilast dilates retinal blood vessels through cyclooxygenase-dependent mechanisms in rats in vivo.
Noguchi
Masahiro
M
Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences, 5-9-1 Shirokane,Minato-ku, Tokyo 108-8641, Japan.
Mori
Asami
A
Sakamoto
Kenji
K
Nakahara
Tsutomu
T
Ishii
Kunio
K
D000758:Anesthesia; D000818:Animals; D008297:Male; D011725:Pyridines / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012171:Retinal Vessels / Q000187:drug effects*; D014665:Vasodilator Agents / Q000494:pharmacology*; D007212:Indolizines; D011720:Pyrazoles
D011725:Pyridines; D014665:Vasodilator Agents; C038366:ibudilast; D007212:Indolizines; D011720:Pyrazoles