Purpose: To evaluate the ocular
hypotensive effects induced by
topical application of anti-glaucoma agents in
mice. Methods: Representative
drugs (
latanoprost and
tafluprost [for
prostanoid FP receptor agonists],
timolol [for
beta-adrenoceptor antagonists],
dipivefrin [for alphabeta-adrenoceptor
agonists],
dorzolamide [for
carbonic anhydrase inhibitors], pilocarpine [for
muscarinic receptor agonists],
bunazosin [for alpha(1)-
adrenoceptor antagonists], or
brimonidine [for alpha(2)-
adrenoceptor agonists]) were used as anti-glaucoma agents; each one being
topically applied once in a given male ddY
mouse.
Intraocular pressure (IOP) was measured using the microneedle method under
general anesthesia. IOP was measured before, and at 1, 2, 3, and 4 h after administration of each
drug. The
contralateral eyes were untreated. At the each time point, the induced IOP reduction was evaluated by calculating the difference in IOP between the treated and untreated
eyes in one and the same
mouse. Results: All of the evaluated anti-glaucoma agents reduced IOP in
mice. The 2
prostanoid FP receptor agonists, the
beta-adrenoceptor antagonist, and the alphabeta-adrenoceptor
agonist began significantly to reduce IOP 2 h after their administration, and mostly induced a long-lasting IOP reduction. The alpha(1)-
adrenoceptor antagonist, the alpha(2)-
adrenoceptor agonist, the
muscarinic receptor agonist, and the
carbonic anhydrase inhibitor began reducing the IOP within 1 h after their administration, but their effects waned fairly quickly (the IOP reductions being lost by 3 h after their administration).
Concomitant administration of
timolol and
tafluprost or of
dorzolamide and
tafluprost induced a significantly greater IOP reduction than that induced by either of the individual components. Conclusions: In this study, all the anti-glaucoma agents tested had apparent ocular
hypotensive effects in
mice. Our data suggest that
the mouse may be a useful animal for the evaluation of the
pharmacological effects of agents with various anti-glaucoma mechanisms, and for the evaluation of the enhanced ocular
hypotensive effects that may be induced by the
concomitant use of 2 anti-glaucoma agents.
