Effects of topical clonidine on prostaglandin-E(2)-induced aqueous flare elevation in pigmented rabbits.
We evaluated the role of topical clonidine on experimental ocular inflammation. Transcorneal diffusion of prostaglandin (PG) E(2), 7. 09 x 10(-2) mmol/l, with the use of a glass cylinder was employed to produce aqueous flare elevation in pigmented rabbits. Clonidine was topically administered and yohimbine was injected intravenously. Aqueous flare was measured with a laser flare cell meter. Topical instillation of 0.25% clonidine inhibited 89% of PGE(2)-induced aqueous flare elevation. Instillation of clonidine at 60 or 30 min before and 10 min after PGE(2) inhibited flare significantly. Pretreatment with intravenous yohimbine decreased the clonidine-induced inhibition of the flare elevation in a dose-dependent manner. It is possible that the anti-inflammatory action of topical clonidine may be mediated partly by alpha(2)-receptors.
Watanabe
K
K
Department of Ophthalmology, Toyama Medical and Pharmaceutical University, Toyama, Japan.
Hayasaka
S
S
Hiraki
S
S
Matsumoto
M
M
Kadoi
C
C
Nagaki
Y
Y
Hayasaka
Y
Y
D000210:Acute-Phase Reaction / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology; D000316:Adrenergic alpha-Agonists / Q000008:administration & dosage*; D000317:Adrenergic alpha-Antagonists / Q000008:administration & dosage; D000818:Animals; D001082:Aqueous Humor / Q000166:cytology* / Q000187:drug effects; D002452:Cell Count; D003000:Clonidine / Q000008:administration & dosage*; D015232:Dinoprostone / Q000633:toxicity*; D008297:Male; D009883:Ophthalmic Solutions; D011817:Rabbits; D015016:Yohimbine / Q000008:administration & dosage
D000316:Adrenergic alpha-Agonists; D000317:Adrenergic alpha-Antagonists; D009883:Ophthalmic Solutions; D015016:Yohimbine; D015232:Dinoprostone; D003000:Clonidine