2016 年 42 巻 9 号 p. 645-650
Studies in rabbits have been performed to evaluate the intraocular pressure (IOP)-reducing effect of various anti-glaucoma eye drops and eye drops of latanoprost (LP), which is a selective agonist of prostaglandin F receptor (FP). However, the sensitivity and localization of FP receptors in the rabbit eye are different from those in humans, and studying the relationship between IOP regulation and FP receptors in rabbits is important for the evaluation of antiglaucoma eye drops. In this study, we investigated whether stimulation of FP receptors in rabbits affects the regulation of aqueous humour production via β receptors by using the LP and the β-blocker timolol (TM). Ocular hypertension was induced in the rabbits by the infusion of a 5％ glucose solution (15 mL/kg). Although no reduction in IOP was observed after the instillation of saline and 0.005％ LP, 0.5％ TM eye drops significantly reduced IOP. The IOP-reducing effect, as measured by area under the curve (AUC∆IOP) in rabbits treated with TM eye drops, was 81.3％ that of LP 0.005％/TM 0.5％ fixed combination (LTFC) eye drops, and the TM concentration in the aqueous humour following the instillation of LTFC eye drops was similar to that of TM eye drops. These results show that the stimulation of FP receptors affects the production of aqueous humour via β receptors in rabbits, meaning the rabbit model is not suitable for the evaluation of anti-glaucoma eye drops with FP receptor activity, since this drug effect was not observed in humans.
