ArticlePurinergic signalling2006
Stimulation of an alpha1-adrenergic receptor downregulates ecto-5' nucleotidase activity on the apical membrane of RPE cells.
Article in Purinergic signalling, 2006. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 9 papers.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
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Who cites it
9 citing papers in PubMed, 19 citations in OpenAlex.
- Mechanisms of Ion Transport Across the Mouse Retinal Pigment Epithelium Measured In Vitro.Investigative ophthalmology & visual science · 2020Article
- Increased ApPurinergic signalling · 2018Article
- Proteomic identification of mammalian cell surface derived glycosylphosphatidylinositol-anchored proteins through selective glycan enrichment.Proteomics · 2014Article
- Lysosomal alkalinization, lipid oxidation, and reduced phagosome clearance triggered by activation of the P2X7 receptor.FASEB journal : official publication of the Federation of American Societies for Experimental Biology · 2013Article
- Elevated pressure triggers a physiological release of ATP from the retina: Possible role for pannexin hemichannels.Neuroscience · 2008Article
- Purinergic signalling in the subretinal space: a role in the communication between the retina and the RPE.Purinergic signalling · 2008Article
- Stimulation of the P2Y1 receptor up-regulates nucleoside-triphosphate diphosphohydrolase-1 in human retinal pigment epithelial cells.The Journal of pharmacology and experimental therapeutics · 2007Article
- Purines, the carotid body and respiration.Respiratory physiology & neurobiology · 2007Review
- Glutamate acts at NMDA receptors on fresh bovine and on cultured human retinal pigment epithelial cells to trigger release of ATP.The Journal of physiology · 2006Article
Corrections and comments
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Authors and funding
9 authors at 2 institutions in 2 countries.
Funding
Abstract
The purines ATP and adenosine play an important role in the communication between the photoreceptors and the retinal pigment epithelium (RPE). While the RPE is known to release ATP into subretinal space, the source of extracellular adenosine is unclear. In other tissues, ecto-nucleotidases mediate the consecutive dephosphorylation of ATP to AMP, and AMP is converted to adenosine by ecto-5' nucleotidase (CD73). This study identifies ecto-5' nucleotidase on RPE cells and investigates modulation of enzyme activity. The RPE was the most active site of 5'AMP dephosphorylation in the posterior rat eye. The ecto-5' nucleotidase inhibitor alphabetamADP prevented the production adenosine by the apical membrane of the bovine RPE. Cultured human ARPE-19 cells expressed mRNA and protein for ecto-5' nucleotidase. The production of phosphate from 5'AMP by ARPE-19 cells was inhibited by alphabetamADP, but the ecto-alkaline phosphatase inhibitor levamisole had no effect. Degradation of 5'AMP was blocked by norepinephrine, epinephrine and phenylephrine, with inhibition by antagonists prazosin and corynanthine implicating the alpha1 adrenergic receptor. The block of enzyme activity by norepinephrine was rapid, occurring within 1 min, and was similar at both 4 and 37 degrees C, consistent with cleavage of the enzyme from its GPI anchor. HPLC measurements indicated norepinephrine reduced levels of adenosine in the bath. In the apical face of the bovine-RPE eyecup, norepinephrine reduced the production of phosphate from 5'AMP, suggesting that both receptor and enzyme face sub-retinal space. In conclusion, RPE cells express ecto-5' nucleotidase, with activity on the apical membrane, and stimulation of alpha-1 adrenergic receptors downregulates activity. As epinephrine is released at light onset, and adenosine can inhibit phagocytosis, the corresponding decrease in subretinal adenosine levels may contribute to the enhanced the phagocytosis of rod outer segments that occurs at this time.
Identifiers
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.