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Role of central muscarinic cholinergic receptors in the formalin-induced pain in rats

OBJECTIVES: In the present study, central effects of physostigmine and atropine have investigated in the formalin-induced pain in rats. MATERIALS AND METHODS: In conscious rats implanted with an intracerebroventricular (i.c.v.) cannula, the effects of i.c.v. injection of physostigmine and atropine w...

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Detalles Bibliográficos
Autores principales: Mojtahedin, Ali, Tamaddonfard, Esmaeal, Zanbouri, Ali
Formato: Texto
Lenguaje:English
Publicado: Medknow Publications 2009
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2861817/
https://www.ncbi.nlm.nih.gov/pubmed/20442824
http://dx.doi.org/10.4103/0253-7613.55205
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author Mojtahedin, Ali
Tamaddonfard, Esmaeal
Zanbouri, Ali
author_facet Mojtahedin, Ali
Tamaddonfard, Esmaeal
Zanbouri, Ali
author_sort Mojtahedin, Ali
collection PubMed
description OBJECTIVES: In the present study, central effects of physostigmine and atropine have investigated in the formalin-induced pain in rats. MATERIALS AND METHODS: In conscious rats implanted with an intracerebroventricular (i.c.v.) cannula, the effects of i.c.v. injection of physostigmine and atropine were investigated on the formalin test in the rat. Formalin test was induced by subcutaneous (s.c.) injection of formalin (50 μl, 1%) in ventral surface of left hind paw, and durations of licking and biting of the injected paw were measured in 5-min blocks for 1 h. RESULTS: Formalin produced a biphasic response (first phase: 0–5 and second phase: 15–40 min) in durations of licking and biting of the injected paw. Physostigmine at doses of 2.5, 5 and 10 ug significantly (P < 0.05) attenuated both first and second phases of pain response. Atropine (5 and 10 ug), used alone, produced no significant effect on pain, but pretreatment with atropine (10 ug) significantly (P < 0.05) blocked antinociception induced by physostigmine (5 ug). CONCLUSION: These results indicate that i.c.v. physostigmine can affect both neurogenic and inflammatory phases of formalin-induced pain through a mechanism in which the muscarinic cholinergic receptors are involved.
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spelling pubmed-28618172010-05-04 Role of central muscarinic cholinergic receptors in the formalin-induced pain in rats Mojtahedin, Ali Tamaddonfard, Esmaeal Zanbouri, Ali Indian J Pharmacol Short Communication OBJECTIVES: In the present study, central effects of physostigmine and atropine have investigated in the formalin-induced pain in rats. MATERIALS AND METHODS: In conscious rats implanted with an intracerebroventricular (i.c.v.) cannula, the effects of i.c.v. injection of physostigmine and atropine were investigated on the formalin test in the rat. Formalin test was induced by subcutaneous (s.c.) injection of formalin (50 μl, 1%) in ventral surface of left hind paw, and durations of licking and biting of the injected paw were measured in 5-min blocks for 1 h. RESULTS: Formalin produced a biphasic response (first phase: 0–5 and second phase: 15–40 min) in durations of licking and biting of the injected paw. Physostigmine at doses of 2.5, 5 and 10 ug significantly (P < 0.05) attenuated both first and second phases of pain response. Atropine (5 and 10 ug), used alone, produced no significant effect on pain, but pretreatment with atropine (10 ug) significantly (P < 0.05) blocked antinociception induced by physostigmine (5 ug). CONCLUSION: These results indicate that i.c.v. physostigmine can affect both neurogenic and inflammatory phases of formalin-induced pain through a mechanism in which the muscarinic cholinergic receptors are involved. Medknow Publications 2009-06 /pmc/articles/PMC2861817/ /pubmed/20442824 http://dx.doi.org/10.4103/0253-7613.55205 Text en © Indian Journal of Pharmacology http://creativecommons.org/licenses/by/2.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Short Communication
Mojtahedin, Ali
Tamaddonfard, Esmaeal
Zanbouri, Ali
Role of central muscarinic cholinergic receptors in the formalin-induced pain in rats
title Role of central muscarinic cholinergic receptors in the formalin-induced pain in rats
title_full Role of central muscarinic cholinergic receptors in the formalin-induced pain in rats
title_fullStr Role of central muscarinic cholinergic receptors in the formalin-induced pain in rats
title_full_unstemmed Role of central muscarinic cholinergic receptors in the formalin-induced pain in rats
title_short Role of central muscarinic cholinergic receptors in the formalin-induced pain in rats
title_sort role of central muscarinic cholinergic receptors in the formalin-induced pain in rats
topic Short Communication
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2861817/
https://www.ncbi.nlm.nih.gov/pubmed/20442824
http://dx.doi.org/10.4103/0253-7613.55205
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