Antinociception synergy between the peripheral and spinal sites of the heme oxygenase-carbon monoxide pathway

We have shown that the peripheral and spinal cord heme oxygenase (HO)-carbon monoxide (CO)-soluble guanylate cyclase-cGMP pathways play an important role in antinociception in the rat experimental formalin model. Our objective was to determine if there is synergism between peripheral (paw) and spina...

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Main Authors: C.G.O. Nascimento, L.G.S. Branco
Format: Article
Language:English
Published: Associação Brasileira de Divulgação Científica 2009-01-01
Series:Brazilian Journal of Medical and Biological Research
Subjects:
Online Access:http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2009000100020
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author C.G.O. Nascimento
L.G.S. Branco
author_facet C.G.O. Nascimento
L.G.S. Branco
author_sort C.G.O. Nascimento
collection DOAJ
description We have shown that the peripheral and spinal cord heme oxygenase (HO)-carbon monoxide (CO)-soluble guanylate cyclase-cGMP pathways play an important role in antinociception in the rat experimental formalin model. Our objective was to determine if there is synergism between peripheral (paw) and spinal HO-CO pathways in nociception. Rats were handled and adapted to the experimental environment for a few days before the formalin test, in which 50 µL of a 1% formalin was injected subcutaneously into the dorsal surface of the right hind paw. The animals were then observed for 1 h and the frequency of flinching behavior was taken to represent the nociceptive response. Thirty minutes before the test, rats were pretreated with intrathecal injections of the HO inhibitor, zinc deuteroporphyrin 2,4-bis glycol (ZnDPBG) or heme-lysinate, which is a substrate of the HO pathway. The paw treatments took place 20 min before the test. Low doses of ZnDPBG did not increase nociception, while a low heme-lysinate dose did not change flinching behavior after paw or spinal injections. Combined subactive spinal (50 nmol) and peripheral (40 nmol) low doses of ZnDPBG induced hypernociception (increase of 80% in the first and 25% in the second phase flinching), whereas combined spinal-peripheral heme-lysinate (50 and 30 nmol) led to second phase antinociception (40% reduction in flinching). These findings suggest a synergy between the peripheral and spinal HO-CO pathways. Local activation of the HO system probably regulates the nociception initiation in peripheral tissue and participates in buffering the emerging nociceptive signals at the peripheral and spinal sites of action. In short, an antinociceptive synergy exists between peripheral and spinal HO pathways, which may reduce the doses required and side effects.
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spelling doaj.art-b1c2f61ecdb7493da5cf7384a604f3bd2022-12-22T01:13:48ZengAssociação Brasileira de Divulgação CientíficaBrazilian Journal of Medical and Biological Research0100-879X1414-431X2009-01-01421141147Antinociception synergy between the peripheral and spinal sites of the heme oxygenase-carbon monoxide pathwayC.G.O. NascimentoL.G.S. BrancoWe have shown that the peripheral and spinal cord heme oxygenase (HO)-carbon monoxide (CO)-soluble guanylate cyclase-cGMP pathways play an important role in antinociception in the rat experimental formalin model. Our objective was to determine if there is synergism between peripheral (paw) and spinal HO-CO pathways in nociception. Rats were handled and adapted to the experimental environment for a few days before the formalin test, in which 50 µL of a 1% formalin was injected subcutaneously into the dorsal surface of the right hind paw. The animals were then observed for 1 h and the frequency of flinching behavior was taken to represent the nociceptive response. Thirty minutes before the test, rats were pretreated with intrathecal injections of the HO inhibitor, zinc deuteroporphyrin 2,4-bis glycol (ZnDPBG) or heme-lysinate, which is a substrate of the HO pathway. The paw treatments took place 20 min before the test. Low doses of ZnDPBG did not increase nociception, while a low heme-lysinate dose did not change flinching behavior after paw or spinal injections. Combined subactive spinal (50 nmol) and peripheral (40 nmol) low doses of ZnDPBG induced hypernociception (increase of 80% in the first and 25% in the second phase flinching), whereas combined spinal-peripheral heme-lysinate (50 and 30 nmol) led to second phase antinociception (40% reduction in flinching). These findings suggest a synergy between the peripheral and spinal HO-CO pathways. Local activation of the HO system probably regulates the nociception initiation in peripheral tissue and participates in buffering the emerging nociceptive signals at the peripheral and spinal sites of action. In short, an antinociceptive synergy exists between peripheral and spinal HO pathways, which may reduce the doses required and side effects.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2009000100020NociceptionCarbon monoxideFormalinHypernociceptionAntinociception
spellingShingle C.G.O. Nascimento
L.G.S. Branco
Antinociception synergy between the peripheral and spinal sites of the heme oxygenase-carbon monoxide pathway
Brazilian Journal of Medical and Biological Research
Nociception
Carbon monoxide
Formalin
Hypernociception
Antinociception
title Antinociception synergy between the peripheral and spinal sites of the heme oxygenase-carbon monoxide pathway
title_full Antinociception synergy between the peripheral and spinal sites of the heme oxygenase-carbon monoxide pathway
title_fullStr Antinociception synergy between the peripheral and spinal sites of the heme oxygenase-carbon monoxide pathway
title_full_unstemmed Antinociception synergy between the peripheral and spinal sites of the heme oxygenase-carbon monoxide pathway
title_short Antinociception synergy between the peripheral and spinal sites of the heme oxygenase-carbon monoxide pathway
title_sort antinociception synergy between the peripheral and spinal sites of the heme oxygenase carbon monoxide pathway
topic Nociception
Carbon monoxide
Formalin
Hypernociception
Antinociception
url http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2009000100020
work_keys_str_mv AT cgonascimento antinociceptionsynergybetweentheperipheralandspinalsitesofthehemeoxygenasecarbonmonoxidepathway
AT lgsbranco antinociceptionsynergybetweentheperipheralandspinalsitesofthehemeoxygenasecarbonmonoxidepathway