Characterization of the P2 receivers in eosinophils of rats and possible functional papers.

by Pinto Alberto, Anael Viana

Abstract (Summary)
ATP and other nucleotides can be released from cells throughregulated pathways or following the loss of plasma membrane integrity. Onceoutside the cell, these compounds take on new roles as intercellular signalingmolecules that elicit a broad spectrum of physiological responses through theactivation of numerous cell surface receptors. These nucleotides act on P2family of receptors that respond by P2X ionotropic receptors and G proteincoupledP2Y receptors. These receptors have been characterized in many ratimmune cells. However, there is a lack on yhe literature concerning to thecharacterization characterization of these receptors in eosinophils. These cellsare involved in asthma and pathological and physiological processes. Dispite ofthat, we investigate, using different techniques, the expression of the P2receptors in eosinophils. Our first step was to investigate the expression of P2Xreceptors (ionotropic) using electrophysiology thecnique. The results with themaximum current amplitude normalized gave us the following ranking of agonistpotency: ATPgt; ATPamp;#947;Sgt; 2meSATPgt; ADPgt; amp;#945;amp;#946;meATPgt; amp;#946;amp;#947;meATPgt; BzATPgt;UTPgt; UDPgt; cAMP, suggesting the presence of P2X2, P2X4. Following thecharacterization, intracellular calcium measurements were performed. Weobtained the follow ranking order of potency: UTPgt; ATPamp;#947;S gt; ADP gt; UDPgt; ATPgt; BzATP gt;2meSATP gt; amp;#945;amp;#946;meATP gt; cAMP gt;Adenosine gt; amp;#946;amp;#947;meATP. Moreover,we did some immunofluorescence assays to corroborate our results and ourdata showed the presence of P2X1, P2X2, P2X4 and P2Y1, P2Y2, P2Y4. Ournext step was to verify the participation of these receptors in the in vitromigration of eosinophils by transwell, in these experiments the ATP was able toincrease migration, an effect which could be blocked by suramin a generalblocker of P2 receptors. Furthermore, we employed a model of rat allergicpleurisy to confirm our findings that P2 receptors are implicated in the migrationof eosinophils to an inflammation site. Our results indicate that suramindecreased the number of cells per cavity, showing the participation of the P2receptors.xiiiWe have demonstrated for the first time that rat eosinophils expressP2X and P2Y and the activation of these receptors can increase migration ofeosinophils in vitro and in vivo.
This document abstract is also available in Portuguese.
Bibliographical Information:

Advisor:Luiz Anastácio Alves

School:Faculdades Oswaldo Cruz

School Location:Brazil

Source Type:Master's Thesis

Keywords: Eletrofisiologia Pleurisia Eosinophils Electrophysiology Fluorescent Antibody Technique Migration Pleurisy


Date of Publication:

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