Evidence for the existence of pyrimidinergic transmission in rat brain

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Date

2015-04

Journal Title

Journal ISSN

Volume Title

Publisher

Pergamon-Elsevier Science

Abstract

The uridine nucleotides uridine-5'-triphosphate (UTP) and uridine-5'-diphosphate (UDP) have previously been identified in media from cultured cells. However, no study to date has demonstrated their presence in brain extracellular fluid (ECF) obtained in vivo. Using a novel method, we now show that UTP and UDP, as well as uridine, are detectable in dialysates of striatal ECF obtained from freely-moving rats. Intraperitoneal (i.p.) administration of uridine or exposure of striatum to depolarizing concentrations of potassium chloride increases extracellular uridine, UTP and UDP, while tetrodotoxin (TTX) decreases their ECF levels. Uridine administration also enhances cholinergic neurotransmission which is accompanied by enhanced brain levels of diacylglycerol (DAG) and inositol trisphosphate (IP3) and blocked by suramin, but not by PPADS (pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid) or MRS2578 suggesting a possible mediation of P2Y2 receptors activated by UTP. These observations suggest that uridine, UTP and UDP may function as pyrimidinergic neurotransmitters, and that enhancement of such neurotransmission underlies pharmacologic effects of exogenous uridine on the brain.

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Keywords

Neurosciences & neurology, Pharmacology & pharmacy, Uridine, UTP, UDP, Pyrimidinergic, Neurotransmission, P2Y receptors, Uridine nucleotide receptor, CDP-choline levels, P2Y receptors, Docosahexaenoic acid, Alzheimers-disease, Functional expression, Phospholipase-C, Nervous-system, Ecto-atpase, Cells, Acetylcholine, Animals, Brain chemistry, Choline, Corpus striatum, Extracellular fluid, Male, Rats, Rats, Sprague-Dawley, Receptors, purinergic P2Y, Uridine, Uridine diphosphate, Uridine triphosphate

Citation

Cansev, M. vd. (2015). "Evidence for the existence of pyrimidinergic transmission in rat brain". Neuropharmacology, 91, 77-86.