Effects of endothelin-1 on intraocular pressure and aqueous humor dynamics in the rabbit eye.
The effects of endothelin-1 (ET-1) on intraocular pressure (IOP) and aqueous humor dynamics were studied in the rabbit eye. The intravitreal injection of 10(-5) M ET-1 (20 microliters) produced a biphasic IOP response consisting of an initial rise of 1 to 2 hours in duration, and a subsequent prolonged reduction lasting for more than 96 hours. Aqueous humor dynamics were determined 24 hours after the 10(-5) M ET-1 injection. Aqueous humor formation, measured fluorophotometrically, was decreased by 58%. Total outflow facility increased by 94%, according to measurement by two-level constant pressure perfusion. The change of uveoscleral outflow determined by fluorescein-dextran perfusion was not significant. The decrease in aqueous flow and the increase in total facility accounted for most of the IOP reduction after the ET-1 injection. Endothelin, which is endogenously present in the eye, may play a role in the regulation of intraocular pressure.
Taniguchi
T
T
Department of Ophthalmology, Gifu University School of Medicine, Japan.
Okada
K
K
Haque
M S
MS
Sugiyama
K
K
Kitazawa
Y
Y
D000818:Animals; D001082:Aqueous Humor / Q000378:metabolism*; D003911:Dextrans / Q000378:metabolism; D016232:Endothelins / Q000494:pharmacology*; D005260:Female; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives / Q000378:metabolism; D015590:Fluorophotometry; D007429:Intraocular Pressure / Q000187:drug effects*; D008297:Male; D010477:Perfusion; D011817:Rabbits; D014822:Vitreous Body
D003911:Dextrans; D016232:Endothelins; C015219:fluorescein isothiocyanate dextran; D016650:Fluorescein-5-isothiocyanate