||EFFECT OF DORZOLAMIDE ON RABBIT OCULAR BLOOD FLOW AND ISOLATED CILIARY ARTERY
WATANABE, Shun ,
ISHIKAWA, MakotoYOSHITOMI, Takeshi
135 , 2016-03-31 , 秋田医学会
BackgroundDorzolamide, the carbonic anhydrase inhibitor, has been reported to have effects on ocular bloodflow other than decreasing intraocular pressure (IOP). We investigated the effects of dorzolamideon the phenylephrine induced impairment of rabbit optic nerve head (ONH) blood flow andon phenylephrine induced contraction in isolated rabbit ciliary artery in vitro.MethodIn male Dutch rabbits, dorzolamide was topically administered after phenylephrine hydrochlorideinstillation. ONH blood flow was measured by the laser speckle method, which expresses bloodvelocity as a quantitative index, the mean blur rate (MBR). Also, we investigated the effects ofdorzolamide on phenylephrine-induced contractions in rabbit ciliary artery in vitro using isometrictension recording method.ResultsMBR showed a maximum decrease by 10% compared to that in the baseline value at 120 min afterphenylephrine instillation. The phenylephrine-induced decrease was significantly inhibited bydorzolamide at 120 min (P=0.0124). The IOP in the dorzolamide-treated eyes was significantlyreduced after phenylephrine instillation. Dorzolamide (30 μM) did not have effect on isolatedrabbit ciliary artery which was pre-contracted with 10 μM phenylephrine.ConclusionTopical dorzolamide inhibited phenylephrine induced decrease of ONH circulation in Dutch rabbits.However, dorzolamide did not have effect on isolated rabbit ciliary artery pre-contractedwith phenylephrine. It is suggested that the dorzolamide improve the ONH blood flow not bydirect action to the vessels.