Nilvadipine inhibits acute rise of aqueous flare and intraocular pressure induced by prostaglandin E2 in pigmented rabbits.
To evaluate the possible role of calcium channel blocker on changes in aqueous flare and intraocular pressure induced by prostaglandin E2 (PGE2) in pigmented rabbits, we examined the effects of nilvadipine and nicardipine (calcium channel blockers). PGE2, 25 micrograms/ml, was administered using a glass cylinder. Nilvadipine or nicardipine was injected intravenously. Aqueous flare was measured by a laser flare cell meter. Intraocular pressure was measured by a noncontact tonometer. After administration of PGE2, aqueous flare and intraocular pressure increased and then decreased. Increased flare and elevated intraocular pressure following PGE2 administration were inhibited by nilvadipine in a dose-dependent manner (5-500 micrograms/kg body weight). These responses were inhibited only slightly by nicardipine at the same concentration. Nilvadipine injected 30 min before PGE2 application inhibited the increase maximally. The inhibitory effect was found on days 1, 3, 5, and 7 by daily administration of nilvadipine. A good correlation between the inhibition of intraocular pressure and the inhibition of increased flare by nilvadipine was found. We believe that Ca2+, or calcium channel blocker-related substances may be involved in the mechanism of PGE2-induced elevation of aqueous flare and intraocular pressure in the pigmented rabbit.
Zhang
X Y
XY
Department of Ophthalmology, Toyama Medical and Pharmaceutical University, Japan.
Hiraki
S
S
Hayasaka
S
S
D000818:Animals; D000869:Anterior Eye Segment / Q000187:drug effects; D001082:Aqueous Humor / Q000187:drug effects* / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000008:administration & dosage / Q000494:pharmacology*; D015232:Dinoprostone / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D005136:Eye Proteins / Q000378:metabolism; D007275:Injections, Intravenous; D007429:Intraocular Pressure / Q000187:drug effects*; D008297:Male; D009529:Nicardipine / Q000008:administration & dosage / Q000494:pharmacology; D009543:Nifedipine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D009883:Ophthalmic Solutions; D011817:Rabbits; D014065:Tonometry, Ocular
D002121:Calcium Channel Blockers; D005136:Eye Proteins; D009883:Ophthalmic Solutions; C035100:nilvadipine; D009529:Nicardipine; D009543:Nifedipine; D015232:Dinoprostone