Characterisation of an uridine-specific binding site in rat cerebrocortical homogenates.

@article{citeulike:2447539, abstract = {Parameters of [3H]uridine binding to synaptic membranes isolated from rat brain cortex (K(D)=71+/-4 nM, B(max)=1.37+/-0.13 pmol/mg protein) were obtained. Pyrimidine and purine analogues displayed different rank order of potency in displacement of specifically bound [3H]uridine (uridine>5-F-uridine>5-Br-uridine approximately adenosine>>5-ethyl-uridine approximately suramin>theophylline) and in the inhibition of [14C]uridine uptake (adenosine>uridine>5-Br-uridine approximately 5-F-uridine approximately 5-ethyl-uridine) into purified cerebrocortical synaptosomes. Furthermore, the effective ligand concentration for the inhibition of [14C]uridine uptake was about two order of magnitude higher than that for the displacement of specifically bound [3H]uridine. Adenosine evoked the transmembrane Na(+) ion influx, whereas uridine the transmembrane Ca(2+) ion influx much more effectively. Also, uridine was shown to increase free intracellular Ca(2+) ion levels in hippocampal slices by measuring Calcium-Green fluorescence. Uridine analogues were found to be ineffective in displacing radioligands that were bound to various glutamate and adenosine-recognition and modulatory-binding sites, however, increased [35S]GTPgammaS binding to membranes isolated from the rat cerebral cortex. These findings provide evidence for a rather specific, G-protein-coupled site of excitatory action for uridine in the brain.}, address = {Department of Neurochemistry, Chemical Research Center, Hungarian Academy of Sciences, 1025 Pusztaszeri \'{u}t 59-67, Budapest, Hungary.}, author = {Kov\'{a}cs, I. and Laszt\'{o}czi, B. and Sz\'{a}rics, E. and H\'{e}ja, L. and S\'{a}gi, G. and Kardos, J. }, citeulike-article-id = {2447539}, issn = {0197-0186}, journal = {Neurochem Int}, keywords = {binding, receptor, uridine}, month = {July}, number = {2}, pages = {101--112}, posted-at = {2008-02-29 12:10:50}, priority = {2}, title = {Characterisation of an uridine-specific binding site in rat cerebrocortical homogenates.}, url = {http://view.ncbi.nlm.nih.gov/pubmed/12620278}, volume = {43}, year = {2003} }

TY - JOUR ID - citeulike:2447539 L3 - citeulike-article-id:2447539 TI - Characterisation of an uridine-specific binding site in rat cerebrocortical homogenates. JF - Neurochem Int VL - 43 IS - 2 SP - 101 EP - 112 AD - Department of Neurochemistry, Chemical Research Center, Hungarian Academy of Sciences, 1025 Pusztaszeri út 59-67, Budapest, Hungary. SN - 0197-0186 N2 - Parameters of [3H]uridine binding to synaptic membranes isolated from rat brain cortex (K(D)=71+/-4 nM, B(max)=1.37+/-0.13 pmol/mg protein) were obtained. Pyrimidine and purine analogues displayed different rank order of potency in displacement of specifically bound [3H]uridine (uridine>5-F-uridine>5-Br-uridine approximately adenosine>>5-ethyl-uridine approximately suramin>theophylline) and in the inhibition of [14C]uridine uptake (adenosine>uridine>5-Br-uridine approximately 5-F-uridine approximately 5-ethyl-uridine) into purified cerebrocortical synaptosomes. Furthermore, the effective ligand concentration for the inhibition of [14C]uridine uptake was about two order of magnitude higher than that for the displacement of specifically bound [3H]uridine. Adenosine evoked the transmembrane Na(+) ion influx, whereas uridine the transmembrane Ca(2+) ion influx much more effectively. Also, uridine was shown to increase free intracellular Ca(2+) ion levels in hippocampal slices by measuring Calcium-Green fluorescence. Uridine analogues were found to be ineffective in displacing radioligands that were bound to various glutamate and adenosine-recognition and modulatory-binding sites, however, increased [35S]GTPgammaS binding to membranes isolated from the rat cerebral cortex. These findings provide evidence for a rather specific, G-protein-coupled site of excitatory action for uridine in the brain. KW - binding KW - receptor KW - uridine AU - Kovács, I AU - Lasztóczi, B AU - Szárics, E AU - Héja, L AU - Sági, G AU - Kardos, J PY - 2003/07// UR - http://view.ncbi.nlm.nih.gov/pubmed/12620278 ER -