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D2-like receptor activation does not initiate a brain docosahexaenoic acid signal in unanesthetized rats

BACKGROUND: The polyunsaturated fatty acid, docosahexaenoic acid (DHA), participates in neurotransmission involving activation of calcium-independent phospholipase A(2) (iPLA(2)), which is coupled to muscarinic, cholinergic and serotonergic neuroreceptors. Drug induced activation of iPLA(2) can be m...

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Autores principales: Taha, Ameer Y, Chang, Lisa, Chen, Mei, Rapoport, Stanley I, Ramadan, Epolia
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4295280/
https://www.ncbi.nlm.nih.gov/pubmed/25359512
http://dx.doi.org/10.1186/1471-2202-15-113
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author Taha, Ameer Y
Chang, Lisa
Chen, Mei
Rapoport, Stanley I
Ramadan, Epolia
author_facet Taha, Ameer Y
Chang, Lisa
Chen, Mei
Rapoport, Stanley I
Ramadan, Epolia
author_sort Taha, Ameer Y
collection PubMed
description BACKGROUND: The polyunsaturated fatty acid, docosahexaenoic acid (DHA), participates in neurotransmission involving activation of calcium-independent phospholipase A(2) (iPLA(2)), which is coupled to muscarinic, cholinergic and serotonergic neuroreceptors. Drug induced activation of iPLA(2) can be measured in vivo with quantitative autoradiography using (14)C-DHA as a probe. The present study used this approach to address whether a DHA signal is produced following dompaminergic (D)2-like receptor activation with quinpirole in rat brain. Unanesthetized rats were infused intravenously with (14)C-DHA one minute after saline or quinpirole infusion, and serial blood samples were collected over a 20-minute period to obtain plasma. The animals were euthanized with sodium pentobarbital and their brains excised, coronally dissected and subjected to quantitative autoradiography to derive the regional incorporation coefficient, k*, a marker of DHA signaling. Plasma labeled and unlabeled unesterified DHA concentrations were measured. RESULTS: The incorporation coefficient (k*) for DHA did not differ significantly between quinpirole-treated and control rats in any of 81 identified brain regions. Plasma labeled DHA concentration over the 20-minute collection period (input function) and unlabeled unesterified DHA concentration did not differ significantly between the two groups. CONCLUSION: These findings demonstrate that D2-like receptor initiated signaling does not involve DHA as a second messenger, and likely does not involve iPLA(2) activation. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1471-2202-15-113) contains supplementary material, which is available to authorized users.
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spelling pubmed-42952802015-01-16 D2-like receptor activation does not initiate a brain docosahexaenoic acid signal in unanesthetized rats Taha, Ameer Y Chang, Lisa Chen, Mei Rapoport, Stanley I Ramadan, Epolia BMC Neurosci Research Article BACKGROUND: The polyunsaturated fatty acid, docosahexaenoic acid (DHA), participates in neurotransmission involving activation of calcium-independent phospholipase A(2) (iPLA(2)), which is coupled to muscarinic, cholinergic and serotonergic neuroreceptors. Drug induced activation of iPLA(2) can be measured in vivo with quantitative autoradiography using (14)C-DHA as a probe. The present study used this approach to address whether a DHA signal is produced following dompaminergic (D)2-like receptor activation with quinpirole in rat brain. Unanesthetized rats were infused intravenously with (14)C-DHA one minute after saline or quinpirole infusion, and serial blood samples were collected over a 20-minute period to obtain plasma. The animals were euthanized with sodium pentobarbital and their brains excised, coronally dissected and subjected to quantitative autoradiography to derive the regional incorporation coefficient, k*, a marker of DHA signaling. Plasma labeled and unlabeled unesterified DHA concentrations were measured. RESULTS: The incorporation coefficient (k*) for DHA did not differ significantly between quinpirole-treated and control rats in any of 81 identified brain regions. Plasma labeled DHA concentration over the 20-minute collection period (input function) and unlabeled unesterified DHA concentration did not differ significantly between the two groups. CONCLUSION: These findings demonstrate that D2-like receptor initiated signaling does not involve DHA as a second messenger, and likely does not involve iPLA(2) activation. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1471-2202-15-113) contains supplementary material, which is available to authorized users. BioMed Central 2014-10-30 /pmc/articles/PMC4295280/ /pubmed/25359512 http://dx.doi.org/10.1186/1471-2202-15-113 Text en © Taha et al.; licensee BioMed Central Ltd. 2014 This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
spellingShingle Research Article
Taha, Ameer Y
Chang, Lisa
Chen, Mei
Rapoport, Stanley I
Ramadan, Epolia
D2-like receptor activation does not initiate a brain docosahexaenoic acid signal in unanesthetized rats
title D2-like receptor activation does not initiate a brain docosahexaenoic acid signal in unanesthetized rats
title_full D2-like receptor activation does not initiate a brain docosahexaenoic acid signal in unanesthetized rats
title_fullStr D2-like receptor activation does not initiate a brain docosahexaenoic acid signal in unanesthetized rats
title_full_unstemmed D2-like receptor activation does not initiate a brain docosahexaenoic acid signal in unanesthetized rats
title_short D2-like receptor activation does not initiate a brain docosahexaenoic acid signal in unanesthetized rats
title_sort d2-like receptor activation does not initiate a brain docosahexaenoic acid signal in unanesthetized rats
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4295280/
https://www.ncbi.nlm.nih.gov/pubmed/25359512
http://dx.doi.org/10.1186/1471-2202-15-113
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