Identification of beta-adrenergic receptors in the pigmented mammalian iris-ciliary body diaphragm

Trope, Graham E.; Clark, Barry; Titinchi, Saad Jaber

doi:10.1016/0014-4835(82)90017-3

Cited by 16 publications

(4 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our observations reinforce the findings of Neufeld et al (9) and Trope et al (10), who noted that the presence of melanin in pigmented eyes acts as a site which could bind to topically applied drugs. The obtained results are in accordance with the findings of a recent study (11) which demonstrates that timolol has a high affinity for melanin and dissociates from this pigment very slowly.…”

Section: Discussionsupporting

confidence: 94%

Effects of Adrenergic Agents on Alpha-Chymotrypsin-Induced Ocular Hypertension in Albino and Pigmented Rabbits: A Comparative Study

Himber

Burlet²,

Andermann³

1989

Journal of Ocular Pharmacology and Therapeutics

View full text Add to dashboard Cite

Mplia-chyirotrypsiji-irKïuced ocular hypertension in albino rabbits is widely used as an experimental model to screen potential antiglaucoma drugs. The present study compares the intraocular pressure (IOP) response following the ocular application of single or repeated adrenergic agents in conscious albino and pigmented rabbits. A single instillation of clonidine was not as effective in lowering the IOP in pigmented hypertensive rabbit eyes as in albino hypertensive eyes. Similarly, betaxolol moderately lowered the IOP in albino rabbits but induced a slight response when pigmented rabbits were used as an experimental model.Twice-a-day applications of betaxolol in pigmented hypertensive eyes permitted an identical level of IOP decrease to be reached, as observed in a oneday study in albino rabbits, after at least 6 days of treatment. It has been suggested that the pigmented layers of the iris-ciliary body may act as sites for topically applied antiglaucoma drugs. Non-specific binding could explain in part the frequent discrepancy observed between the preclinical results obtained in albino hypertensive rabbit eyes and clinical results obtained in glaucomatous human eyes.

show abstract

Section: Discussionsupporting

confidence: 94%

Effects of Adrenergic Agents on Alpha-Chymotrypsin-Induced Ocular Hypertension in Albino and Pigmented Rabbits: A Comparative Study

Himber

Burlet²,

Andermann³

1989

Journal of Ocular Pharmacology and Therapeutics

View full text Add to dashboard Cite

show abstract

“…However, pigmented and nonpigmented (albino) rabbits have been utilized most often in glaucoma studies due to the fact that they are economical and easily handled in the laboratory setting. However, some investigators have expressed concern about drugs binding to pigment and concluded that melanin in the iris acts as a binding site for topically applied drugs (8)(9)(10).…”

Section: Discussionmentioning

confidence: 99%

Comparative Effects of Alpha-2 and DA-2 Agonists on Intraocular Pressure in Pigmented and Nonpigmented Rabbits

Ogidigben¹,

Potter²

1993

Journal of Ocular Pharmacology and Therapeutics

View full text Add to dashboard Cite

Alpha-2 and DA2 adrenoceptor agonists produce ocular hypotension in cats, rabbits, monkeys and humans. In this study,the effects of topical, unilateral administration of medetomidine (MED), an alpha-2 agonist, and Ha-118 (HA), a DA2 agonist, were compared on intraocular pressure (IOP) in normal, unilaterally sympathectomized (SX), and ocular hypertensive (oral water loaded) Dutch Belted (DB) and New Zealand White (NZW) rabbits. MED (75pg) produced bilateral ocular hypotensive effects in both DB and NZW normal rabbits; however, HA (250pg) lowered IOP unilaterally in NZW rabbits only . MED (25pg) inhibited the rise in IOP caused by oral water loading in both DB and NZW rabbits; HA, on the other hand, was effective only in NZW rabbits.

show abstract

“…Melanin was isolated from bovine eyes according to Trope et al (1982), with small modifications. Melanin was isolated from bovine eyes according to Trope et al (1982), with small modifications.…”

Section: Methodsmentioning

confidence: 99%

“…Melanin was isolated from bovine eyes according to Trope et al (1982), with small modifications. Irides were dissected and pigment epithelium separated under preparation microscope.…”

Section: Preparation Of Bovine Ocular Melaninmentioning

confidence: 99%

Prostaglandin F_2α Binding to Bovine Ocular and Synthetic Melanins in Vitro

Aula

Kaila

Huupponen

et al. 1989

Pharmacology & Toxicology

View full text Add to dashboard Cite

The binding of 3H-prostaglandin F2 alpha to bovine iris and synthetic melanin was studied in vitro using a ligand binding assay. Prostaglandin F2 alpha was reversibly bound to both types of melanin. The binding was saturable and the Scatchard analysis revealed the existence of at least two binding sites with the corresponding K(D) values of 3.71 nM and 1.99 microM for natural and 4.99 nM and 0.19 microM for synthetic melanin, respectively. The high affinity Bmax values were 3.4 nM/g for natural and 2.5 nM/g for synthetic melanin. The dissociation of prostaglandin F2 alpha from melanin after dilution of the complex was rapid and uniform.

show abstract

Identification of beta-adrenergic receptors in the pigmented mammalian iris-ciliary body diaphragm

Cited by 16 publications

References 4 publications

Effects of Adrenergic Agents on Alpha-Chymotrypsin-Induced Ocular Hypertension in Albino and Pigmented Rabbits: A Comparative Study

Effects of Adrenergic Agents on Alpha-Chymotrypsin-Induced Ocular Hypertension in Albino and Pigmented Rabbits: A Comparative Study

Comparative Effects of Alpha-2 and DA-2 Agonists on Intraocular Pressure in Pigmented and Nonpigmented Rabbits

Prostaglandin F_2α Binding to Bovine Ocular and Synthetic Melanins in Vitro

Contact Info

Product

Resources

About

Identification of beta-adrenergic receptors in the pigmented mammalian iris-ciliary body diaphragm

Cited by 16 publications

References 4 publications

Effects of Adrenergic Agents on Alpha-Chymotrypsin-Induced Ocular Hypertension in Albino and Pigmented Rabbits: A Comparative Study

Effects of Adrenergic Agents on Alpha-Chymotrypsin-Induced Ocular Hypertension in Albino and Pigmented Rabbits: A Comparative Study

Comparative Effects of Alpha-2 and DA-2 Agonists on Intraocular Pressure in Pigmented and Nonpigmented Rabbits

Prostaglandin F2α Binding to Bovine Ocular and Synthetic Melanins in Vitro

Contact Info

Product

Resources

About

Prostaglandin F_2α Binding to Bovine Ocular and Synthetic Melanins in Vitro