Ocular effects of clonidine in cats and monkeys (Macaca irus)

Bill, Anders; Heilmann, K

doi:10.1016/0014-4835(75)90129-3

Cited by 49 publications

(9 citation statements)

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“…For example, a-adrenergic antago nists and agonists lower intraocular pressure in experimental animals and man. Further more, some drugs have a biphasic action: hypertensive and hypotensive [1][2][3][4]. aAdrenergic receptors have been character ized in the iris-ciliary body [5] and recently, using selective radioligands, the number of sites of the two receptor subclasses has been determined [6,7]: 70-75% were of the a-> type.…”

Section: Introductionmentioning

confidence: 99%

Alpha₂-Adrenergic Receptors in Rat and Rabbit Eye: A Tritium-Sensitive Film Autoradiography

Elena

Kosina-Boix²,

Denis

et al. 1989

Ophthalmic Res

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Using a tritium-sensitive film and [³H]-clonidine, α-adrenergic receptors were localized in entire eye sections of rabbits and rats. This radioactive agonist specifically labelled three structures in albino animals: ocular muscles, ciliary processes and retina. In pigmented animals, uvea with melanin was intensively but nonspecifically labelled. Microscopic analysis of autoradiograms obtained with irisciliary bodies, revealed that the major localization of binding sites was in the ciliary process epithelium. In displacement studies, [³H]-clonidine binding was inhibited by α₂-adrenergic compounds while α₁- or β-selective drugs had no inhibitory effects.

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Section: Introductionmentioning

confidence: 99%

Alpha₂-Adrenergic Receptors in Rat and Rabbit Eye: A Tritium-Sensitive Film Autoradiography

Elena

Kosina-Boix²,

Denis

et al. 1989

Ophthalmic Res

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“…The injection of clonidine into these vessels causes a marked, dose-dependent increase in lOP. In the same way as after the intravenous administration the initial, transient decrease is due to the constriction of intraocular blood vessels (Bill and Heilmann, 1975).…”

Section: Discussionmentioning

confidence: 90%

“…The rapid decrease of IOP in the first minute is the consequence of vasoconstriction in the uveal region (Bill and Heilmann, 1975). Similarly, vasoconstriction also causes the well-known initial increase in MAP.…”

Section: Discussionmentioning

confidence: 99%

“…It has been attempted to explain this mechanism by means of various hypotheses. According to Bill and Heilmann (1975) the effect of clonidine is secondary to vasoconstriction within the uvea, thus reducing blood flow in this region. In consequence, the intrascleral venous pressure decreases, thus inducing a reduction of intraocular pressure.…”

Section: Introductionmentioning

confidence: 99%

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The influence of clonidine on intraocular pressure

Innemee¹,

Zwieten²

1979

Doc Ophthalmol

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In order to study the influence of clonidine on intraocular pressure (IOP), the drug was administered via different routes. The experiments were performed on chloralose-anaesthetized cats. The rise in IOP observed after administration of clonidine into the external carotid arteries was subjected to a pharmacological analysis. Our experiments suggest that the increase in IOP is due to the contraction of eyelids and extraocular muscles, mediated by the influence of clonidine on alpha-adrenoceptors. The IOP-lowering effect of clonidine was more pronounced after its infusion into the left vertebral artery than after its intravenous injection. This difference would suggest that the clonidine-induced decrease in IOP may be mediated via a central mechanism.

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“…Obstruction to the outflow of aqueous humor from the anterior segment Prostaglandin analogs, beta-adrenergic receptor antagonists, alpha2-adrenergic agonists parasympathomimetics, carbonic anhydrase inhibitors [25][26][27][28][29].…”

Section: Glaucomamentioning

confidence: 99%

Nanoparticulate Transscleral Ocular Drug Delivery

Shah¹,

Shah²,

Groshev³

et al. 2014

J Biomol Res Ther

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Ocular drug delivery is one of the most challenging areas of drug delivery due to the unique mostly avascular nature of the major eye structures and presence of two blood barriers. Effectiveness of a more conventional systemic delivery falls short due to low drug levels in the eye tissue. Periocular approaches require penetration of fibrous sclera and present their own limitations. Utilization of nanotechnology presents new avenue of drug system development with potential to penetrate protective barriers and sustain ample tissue saturation. More specifically, transscleral delivery permits a range of applications in targeted delivery, gene, stem cell, protein and peptides, oligonucleotide, and ribozyme therapies. The exciting range of current applications is expounded in this review.

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Ocular effects of clonidine in cats and monkeys (Macaca irus)

Cited by 49 publications

References 13 publications

Alpha₂-Adrenergic Receptors in Rat and Rabbit Eye: A Tritium-Sensitive Film Autoradiography

Alpha₂-Adrenergic Receptors in Rat and Rabbit Eye: A Tritium-Sensitive Film Autoradiography

The influence of clonidine on intraocular pressure

Nanoparticulate Transscleral Ocular Drug Delivery

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Ocular effects of clonidine in cats and monkeys (Macaca irus)

Cited by 49 publications

References 13 publications

Alpha2-Adrenergic Receptors in Rat and Rabbit Eye: A Tritium-Sensitive Film Autoradiography

Alpha2-Adrenergic Receptors in Rat and Rabbit Eye: A Tritium-Sensitive Film Autoradiography

The influence of clonidine on intraocular pressure

Nanoparticulate Transscleral Ocular Drug Delivery

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Product

Resources

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Alpha₂-Adrenergic Receptors in Rat and Rabbit Eye: A Tritium-Sensitive Film Autoradiography

Alpha₂-Adrenergic Receptors in Rat and Rabbit Eye: A Tritium-Sensitive Film Autoradiography