[Biphasic intraocular pressure response to intravitreal injection of endothelin-1].
Endothelin-1 (ET-1) reduces intraocular pressure (IOP) in animals when administered topically. The time course of IOP induced by ET-1, however, has not been fully elucidated. We studied the IOP response to different doses of ET-1 ranging from 10(-7) to 10(-4)M (5 micrograms to 5 ng) intravitreally injected in rabbits. In each animal one eyes received 20 microliters of ET-1 solution and the contralateral eye received same amount of vehicle in a randomized, masked fashion. IOP was measured by a pneumotonometer prior to and periodically for at least 72 hours after the intravitreal injection. ET-1 in 10(-4) and 10(-5) molar concentration elicited a biphasic IOP response consisting of an initial rise of 1 to 2 hours duration, and a subsequent prolonged reduction lasting for more than 72 hours. 3 x 10(-6) and 10(-6) M solution resulted in a prolonged IOP reduction without an early IOP rise. No significant IOP change was induced by 10(-7) M solution or vehicle. Both IOP rise and reduction were significantly related to the dose of ET-1.
Okada
K
K
Department of Ophthalmology, Gifu University School of Medicine, Japan.
Sugiyama
K
K
Haque
S R
SR
Taniguchi
T
T
Kitazawa
Y
Y
D000818:Animals; D004305:Dose-Response Relationship, Drug; D016232:Endothelins / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D007267:Injections; D007429:Intraocular Pressure / Q000187:drug effects*; D008297:Male; D011817:Rabbits; D011897:Random Allocation; D014822:Vitreous Body
D016232:Endothelins