1991 Fiscal Year Final Research Report Summary
The Effect of alpha_1 Adrenergic Antagonist on Intraocular Pressure and Aqueous Humor Dynamics in Rabbit and Human.
| Project/Area Number |
01570976
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Ophthalmology
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| Research Institution | Osaka University |
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Principal Investigator |
KUWAYAMA Yasuaki Osaka University Medical School, Dept of Ophthalmol. Assistant Professor, 医学部, 助手 (70186568)
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| Project Period (FY) |
1989 – 1990
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| Keywords | Bunazosin hydrochrolide / Alpha_1 antagonist / Intraocular pressure / Aqueous humor / Rabbit / Human / Glaucoma / Alpha adrenergic receptor |
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| Research Abstract |
(1) The effect of bunazosin hydrochrolide, a highly selective alpha_1 adrenergic antagonist, on intraocular pressure (IOP) and aqueous humor dynamics in rabbits was studied. Unilateral administration of bunazosin (0.01%-2.5%) produced dose-dependent decrease in the IOP. Fluorophotometry showed statistically significant increase of the aqueous flow rate after topical bunazosin. The outflow facility, measured by two-level constant pressure method, did not significantly altered. The pupil diameter did not significantly changed by any dose. Superior cervical ganglionectomy totally eliminated the IOP lowering effect of bunazosin.
(2) In sympathectomized eyes, norepinephrine caused a concentration dependent rise in IOP and mydriasis. Pretreatment with bunazosin eliminated the rise in IOP induced by norepinephrine without affecting the norepinephrine-induced mydriasis. These results suggest that alpha_1 adrenoreceptors involved in IOP and pupillaly responses are different subtype.
(3) The effect of topically applied bunazosin hydrochrolide on IOP and aqueous humor dynamics in healthy human volunteers was investigated. Topical 0.1% bunazosin significantly lowered IOP froi 1 to 10 hrs with its maximum at approximately 3 hrs. Fluorophotometrically measured aqueous humor flow rates did not change significantly. Bunazosin caused significant reduction of systolic and diastolic blood pressure 5 hrs after application. A small but significant decrease in pupil diameter and and increase in anterior chamber depth was observed. Pulse rate and refraction were not substantially altered. There was moderate conjunctival vessel dilation, however, no serious complication were encountered.
(4) In conclusion, bunazosin hydrochloride appears to have great clinical potential for glaucoma therapy.
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Research Products
(8 results)
