Neurotransmitter-related features of the retinal pigment epithelium

Bondy, Stephen C.; Ali, Syed F.; Hong, Jau–Shyong; Wilson, William E.; Fletcher, Terace M.; Chader, Gerald J.

doi:10.1016/0197-0186(83)90030-x

Cited by 20 publications

(3 citation statements)

References 46 publications

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“…Light-induced changes in retinal dopamine release and subsequent changes in cAMP levels of the RPE may have a role in mediating aspects of RPE physiology other than pigment movement. In addition to our results suggesting that teleost RPE cells possess D2 dopaminergic receptors, other studies have reported highaffinity binding of [3H]spiperone, a D2 antagonist, to isolated RPE of cow and cat (Bondy et al, 1983;Bruinink et al, 1986). These latter species do not exhibit significant RPE pigment movement.…”

Section: Discussionsupporting

confidence: 77%

Light‐Induced Dopamine Release from Teleost Retinas Acts as a Light‐Adaptive Signal to the Retinal Pigment Epithelium

Dearry

Burnside

1989

Journal of Neurochemistry

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In the retinal pigment epithelium (RPE) of lower vertebrates, melanin pigment granules migrate in and out of the cells' long apical projections in response to changes in light condition. When the RPE is in its normal association with the retina, light onset induces pigment granules to disperse into the apical projections; dark onset induces pigment granules to aggregate into the cell bodies. However, when the RPE is separated from the retina, pigment granule movement in the isolated RPE is insensitive to light onset. It thus seems likely that a signal from the retina communicates light onset to the RPE to initiate pigment dispersion. We have examined the nature of this retina-to-RPE signal in green sunfish, Lepomis cyanellus. In isolated retinas with adherent RPE, light-induced pigment dispersion in the RPE is blocked by treatments known to block Ca2+-dependent transmitter release in the retina. In addition, the medium obtained from incubating previously dark-adapted retinas in the light induces light-adaptive pigment dispersion when added to isolated RPE. In contrast, the medium obtained from incubating dark-adapted retinas in constant darkness does not affect pigment distribution when added to isolated RPE. These results are consistent with the idea that RPE pigment dispersion is triggered by a substance that diffuses from the retina at light onset. The capacity of the conditioned medium from light-incubated retinas to induce pigment dispersion in isolated RPE is inhibited by a D2 dopamine antagonist, but not by D1 or alpha-adrenergic antagonists. Light-induced pigment dispersion in whole RPE-retinas is also blocked by a D2 dopamine antagonist.(ABSTRACT TRUNCATED AT 250 WORDS)

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Section: Discussionsupporting

confidence: 77%

Light‐Induced Dopamine Release from Teleost Retinas Acts as a Light‐Adaptive Signal to the Retinal Pigment Epithelium

Dearry

Burnside

1989

Journal of Neurochemistry

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“…In addition, we have shown that dopamine and epinephrine inhibited forskolin-induced pigment aggregation in isolated RPE-retinas, suggesting that stimulation of either dopaminergic or a-adrenergic receptors acts to inhibit forskolin-stimulated adenylate cyclase activity in RPE (Dearry and Burnside, 1985). Other investigators have demonstrated that D2 dopaminergic and a2-adrenergic receptors can be coupled to adenylate cyclase in an inhibitory manner (see re- views by Creese et al, 1982;Limbird, 1983) and that both dopaminergic and a-adrenergic binding sites are present on RPE (Bondy et al, 1983;Bruinink et al, 1986). Together, these results suggest that dopamine and clonidine produce light-adaptive pigment dispersion by respectively binding to D2 dopaminergic and a2-adrenergic receptors on RPE, thereby inhibiting RPE adenylate cyclase activity.…”

Section: Discussionmentioning

confidence: 81%

Stimulation of Distinct D2 Dopaminergic and α₂‐Adrenergic Receptors Induces Light‐Adaptive Pigment Dispersion in Teleost Retinal Pigment Epithelium

Dearry

Burnside

1988

Journal of Neurochemistry

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In the retinal pigment epithelium (RPE) of lower vertebrates, melanin pigment granules aggregate and disperse in response to changes in light conditions. Pigment granules aggregate into the RPE cell body in the dark and disperse into the long apical projections in the light. Pigment granule movement retains its light sensitivity in vitro only if RPE is explanted together with neural retina. In the absence of retina, RPE pigment granules no longer move in response to light onset or offset. Using a preparation of mechanically isolated fragments of RPE from green sunfish, Lepomis cyanellus, we investigated the effects of catecholamines on pigment migration. We report here that 3,4-dihydoxyphenylethylamine (dopamine) and clonidine each mimic the effect of light in vivo by inducing pigment granule dispersion. Dopamine had a half-maximal effect at approximately 2 nM; clonidine, at 1 microM. Dopamine-induced dispersion was inhibited by the D2 dopaminergic antagonist sulpiride but not by D1 or alpha-adrenergic antagonists. Furthermore, a D2 dopaminergic agonist (LY 171555) but not a D1 dopaminergic agonist (SKF 38393) mimicked the effect of dopamine. Clonidine-induced dispersion was inhibited by the alpha 2-adrenergic antagonist yohimbine but not by sulpiride. These results suggest that teleost RPE cells possess distinct D2 dopaminergic and alpha 2-adrenergic receptors, and that stimulation of either receptor type is sufficient to induce pigment granule dispersion. In addition, forskolin, an activator of adenylate cyclase, induced pigment granule movement in the opposite direction, i.e., dark-adaptive pigment aggregation.(ABSTRACT TRUNCATED AT 250 WORDS)

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“…However, it was necessary to establish the basic binding characteristics of the ligands used. Thus saturability, specificity, and reversibility of different binding sites were delineated (Ali, Slikker, Newport, & Goad, 1986; Bondy et al, 1983).…”

Section: Methodsmentioning

confidence: 99%

Role of dentate gyrus cells in retention of a radial arm maze task and sensitivity of rats to cholinergic drugs.

Tilson¹,

Harry²,

McLamb³

et al. 1988

Behavioral Neuroscience

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Male adult Fischer-344 rats that received bilateral injections of colchicine into two rostrocaudal sites showed relatively long-lasting alterations in the performance of a previously acquired radial arm maze task and specific destruction of dentate granule cells. Results of subsequent experiments with cholinergic drugs indicated that physostigmine or nicotine had no effect on the number of errors made in the maze, although other signs of cholinergic or pharmacological activity were present. RS-86, an analog of the muscarinic agonist arecoline, decreased errors in colchicine-treated rats, but these effects were associated with signs of parasympathetic overstimulation and behavioral sedation. Pretreatment with scopolamine, a muscarinic cholinergic receptor antagonist, increased errors in control rats but had no effect in colchicine-treated rats. Results of subsequent experiments found that colchicine-treated rats were less sensitive to the motor stimulant effect of scopolamine. These effects appeared to be associated with increased levels of choline acetyltransferase in the hippocampus and a down regulation of muscarinic postsynaptic receptors. One interpretation of these data is that intradentate colchicine may destroy granule cells, which leads to a compensatory reinnervation of cholinergic nerve terminals having cell bodies in the septum.

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Neurotransmitter-related features of the retinal pigment epithelium

Cited by 20 publications

References 46 publications

Light‐Induced Dopamine Release from Teleost Retinas Acts as a Light‐Adaptive Signal to the Retinal Pigment Epithelium

Light‐Induced Dopamine Release from Teleost Retinas Acts as a Light‐Adaptive Signal to the Retinal Pigment Epithelium

Stimulation of Distinct D2 Dopaminergic and α₂‐Adrenergic Receptors Induces Light‐Adaptive Pigment Dispersion in Teleost Retinal Pigment Epithelium

Role of dentate gyrus cells in retention of a radial arm maze task and sensitivity of rats to cholinergic drugs.

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Neurotransmitter-related features of the retinal pigment epithelium

Cited by 20 publications

References 46 publications

Light‐Induced Dopamine Release from Teleost Retinas Acts as a Light‐Adaptive Signal to the Retinal Pigment Epithelium

Light‐Induced Dopamine Release from Teleost Retinas Acts as a Light‐Adaptive Signal to the Retinal Pigment Epithelium

Stimulation of Distinct D2 Dopaminergic and α2‐Adrenergic Receptors Induces Light‐Adaptive Pigment Dispersion in Teleost Retinal Pigment Epithelium

Role of dentate gyrus cells in retention of a radial arm maze task and sensitivity of rats to cholinergic drugs.

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Stimulation of Distinct D2 Dopaminergic and α₂‐Adrenergic Receptors Induces Light‐Adaptive Pigment Dispersion in Teleost Retinal Pigment Epithelium