Prostaglandin F2 alpha isopropyl ester versus iloprost phenacyl ester in rabbit and beagle eyes.
One and 2 micrograms of prostaglandin F2 alpha isopropyl ester (PGF2 alpha -IE) applied topically to the rabbit eye caused a biphasic response. The hypotensive phase was dose-dependent with a maximum reduction in intraocular pressure (IOP) of 9.4 +/- 1.7 mmHg at a dose of 2 micrograms. In beagles, 0.4 to 2 micrograms topical PGF2 alpha-IE resulted in a sustained IOP reduction; 2 micrograms produced the maximum reduction of 7-9 mmHg. No initial hypertensive response was observed. Iloprost phenacyl ester (Iloprost-PE) caused a greater decrease in IOP when dissolved in 0.5% hydroxypropyl methylcellulose (AT) than in saline. In rabbits, doses of 0.1 to 1 microgram in AT caused a biphasic response with a sustained IOP decrease fluctuating between 7 and 8 mmHg. In beagles 1 and 2 micrograms Iloprost-PE resulted in a mean IOP reduction of 5.8 +/- 0.4 mmHg and 5.8 +/- 0.5 mmHg (P less than 0.005), respectively; the decrease persisted for 5 hrs. No initial hypertensive response was observed. In beagles PGF2 alpha-IE induced a strong miosis lasting more than 6 hours; Iloprost-PE had no effect on pupil size. Both PG-esters induced a slight hyperemia in rabbit and beagle eyes. In rabbits Iloprost-PE affects the blood-aqueous barrier more than PGF2 alpha-IE, since higher protein concentrations are seen in the aqueous humor after application of Iloprost-PE. Neither PG-ester had a noticeable effect on aqueous protein in beagles. In rabbits, both PG-esters led to slightly increased aqueous humor cyclic-AMP concentrations. In beagles aqueous humor cyclic-AMP was elevated only after Iloprost-PE.(ABSTRACT TRUNCATED AT 250 WORDS)
Groeneboer
M C
MC
Netherlands Ophthalmic Research Institute, Department of Experimental Ophthalmology, Amsterdam.
Hoyng
P F
PF
Kuizenga
A
A
D000287:Administration, Topical; D000818:Animals; D001082:Aqueous Humor / Q000032:analysis; D000242:Cyclic AMP / Q000032:analysis; D015237:Dinoprost / Q000031:analogs & derivatives* / Q000494:pharmacology; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D011464:Epoprostenol / Q000494:pharmacology*; D006940:Hyperemia; D065347:Hypromellose Derivatives; D016285:Iloprost / Q000031:analogs & derivatives*; D007429:Intraocular Pressure / Q000187:drug effects*; D008747:Methylcellulose / Q000031:analogs & derivatives / Q000032:analysis; D011680:Pupil / Q000187:drug effects; D011817:Rabbits; D013997:Time Factors; D014065:Tonometry, Ocular
C059649:iloprost phenacyl ester; D065347:Hypromellose Derivatives; C041158:prostaglandin F2 isopropyl ester; D008747:Methylcellulose; D015237:Dinoprost; D011464:Epoprostenol; D000242:Cyclic AMP; D016285:Iloprost