Abstract
Using in vitro binding methods and autoradiographs, the authors showed that choroidal vessels specifically bind iodine 125 cyanopindolol, a nonselective blocker of beta-adrenergic receptors, in albino rabbits. In humans, the presence of beta-adrenergic receptors in choroidal vessels was confirmed by showing an increased choroidal vascular tone after systemic administration of timolol maleate, a nonselective beta-adrenergic blocker. Topically administered timolol maleate lowered the intraocular pressure but did not reach the choroidal receptors in sufficient quantity to produce a measurable effect on vascular tone.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Administration, Topical
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Adrenergic beta-Antagonists / administration & dosage
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Adrenergic beta-Antagonists / metabolism
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Adult
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Animals
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Autoradiography
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Choroid / blood supply*
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Choroid / metabolism*
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Female
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Hemodynamics / drug effects
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Humans
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Intraocular Pressure / drug effects
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Male
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Middle Aged
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Pigment Epithelium of Eye / metabolism
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Pindolol / analogs & derivatives
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Pindolol / metabolism
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Rabbits
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Receptors, Adrenergic, beta / metabolism*
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Retinal Vessels / metabolism*
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Timolol / administration & dosage
Substances
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Adrenergic beta-Antagonists
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Receptors, Adrenergic, beta
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cyanopindolol
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Timolol
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Pindolol