Stimulation of an alpha1-adrenergic receptor downregulates ecto-5' nucleotidase activity on the apical membrane of RPE cells.

Purinergic Signalling
David ReigadaClaire H Mitchell

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 sim...Continue Reading

References

Aug 1, 1976·Experimental Eye Research·M M LaVail
Jul 15, 1992·The Biochemical Journal·H Zimmermann
Feb 1, 1982·Journal of Neurocytology·G W Kreutzberg, S T Hussain
Nov 1, 1983·Journal of Neurochemistry·M HadjiconstantinouN H Neff
Aug 28, 1995·Brain Research. Developmental Brain Research·N BraunH Zimmermann
Jun 1, 1996·General Pharmacology·J A Thorn, S M Jarvis
Aug 26, 1998·The Journal of Histochemistry and Cytochemistry : Official Journal of the Histochemistry Society·T Takizawa
Oct 25, 2000·The Journal of Immunology : Official Journal of the American Association of Immunologists·S NarravulaS P Colgan
Dec 9, 2000·Naunyn-Schmiedeberg's Archives of Pharmacology·H Zimmermann
May 28, 2002·Molecular and Cellular Biochemistry·Kameljit KalsiRyszard T Smolenski
Sep 17, 2004·American Journal of Physiology. Cell Physiology·David Reigada, Claire H Mitchell
Mar 23, 2005·Experimental Eye Research·David J CollisonJulie Sanderson
Apr 29, 2005·American Journal of Physiology. Cell Physiology·David ReigadaClaire H Mitchell

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Citations

Dec 13, 2016·Experimental Eye Research·Susanne KeckeisOlaf Strauß
Jul 14, 2007·The Journal of Pharmacology and Experimental Therapeutics·Wennan LuClaire H Mitchell
Aug 22, 2013·FASEB Journal : Official Publication of the Federation of American Societies for Experimental Biology·Sonia GuhaClaire H Mitchell
Jun 28, 2018·Purinergic Signalling·María J Pérez de LaraJesús Pintor
Jun 17, 2020·Investigative Ophthalmology & Visual Science·Sunna Bjorg SkarphedinsdottirSighvatur Sævar Árnason

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Methods Mentioned

BETA
electron microscopy
Assay

Software Mentioned

Image Pro Plus
Sigmaplot
SPSS
BLAST

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