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Abstract #6865 Published in IGR 4-1
The effect of topical natural ergot alkaloids on the intraocular pressure and aqueous humor dynamics in rabbits with α-chymotrypsin-induced ocular hypertension
Puras G; Santafe J; Segarra J; Garrido M; Melena JGraefe's Archive for Clinical and Experimental Ophthalmology 2002; 240: 322-328
BACKGROUND: The authors have previously reported that the topical natural ergot alkaloids ergocristine, α-ergocryptine, and ergocornine dose-dependently reduce intraocular pressure (IOP) in ocular normotensive rabbits, most likely by decreasing aqueous humor inflow. In the present study, the effects of these compounds on IOP and aqueous humor dynamics in a rabbit model for ocular hypertension were assessed. METHODS: Experiments were conducted in albino rabbits made ocular hypertensive by intracameral injection of α-chymotrypsin. IOP responses to drug vehicle and seven different doses of topical natural ergot alkaloids were examined in order to obtain dose-response relationships for comparing the IOP-lowering effect and potency of these drugs. Tonography was also performed to ascertain the actions of natural ergot alkaloids on aqueous humor dynamics in α-chymotrypsin-induced ocular hypertensive rabbits. RESULTS: Topical application of the natural ergot alkaloids ergocristine, α-ergocryptine, and ergocornine lowered IOP in α-chymotrypsin-induced ocular hypertensive rabbits in a dose-related fashion, with ergocristine displaying the greatest IOP-lowering effect. Tonographic studies revealed a decrease in the tonographic outflow facility following topical application of natural ergot alkaloids, although only the effects of both ergocristine and α-ergocryptine reached statistical significance. All natural ergot alkaloids tested significantly reduced the calculated aqueous humor inflow. CONCLUSIONS: This study suggests that the natural ergot alkaloids ergocristine, α-ergocyptine, and ergocornine effectively decrease IOP in the α-chymotrypsin-induced model of ocular hypertension. Since these compounds reduce the tonographic aqueous humor outflow facility, their final ocular antihypertensive effect appears to result from a remarkable reduction of the aqueous humor inflow.
Dr. J. Santafe, Department of Pharmacology, Faculty of Pharmacy, Universidad del Pais Vasco, Paseo de la Universidad 7, 01006 Vitoria, Spain. kfpsaorj@vc.ehu.es
Classification:
11.14 Investigational drugs; pharmacological experiments (Part of: 11 Medical treatment)
