Role of nitric oxide in hypoxia-induced hyperventilation and hypothermia: participation of the locus coeruleus

Detalhes bibliográficos
Autor(a) principal: Fabris,G.
Data de Publicação: 1999
Outros Autores: Anselmo-Franci,J.A., Branco,L.G.S.
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Brazilian Journal of Medical and Biological Research
Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999001100009
Resumo: Hypoxia elicits hyperventilation and hypothermia, but the mechanisms involved are not well understood. The nitric oxide (NO) pathway is involved in hypoxia-induced hypothermia and hyperventilation, and works as a neuromodulator in the central nervous system, including the locus coeruleus (LC), which is a noradrenergic nucleus in the pons. The LC plays a role in a number of stress-induced responses, but its participation in the control of breathing and thermoregulation is unclear. Thus, in the present study, we tested the hypothesis that LC plays a role in the hypoxia-induced hypothermia and hyperventilation, and that NO is involved in these responses. Electrolytic lesions were performed bilaterally within the LC in awake unrestrained adult male Wistar rats weighing 250-350 g. Body temperature and pulmonary ventilation (VE) were measured. The rats were divided into 3 groups: control (N = 16), sham operated (N = 7) and LC lesioned (N = 19), and each group received a saline or an NG-nitro-L-arginine methyl ester (L-NAME, 250 µg/µl) intracerebroventricular (icv) injection. No significant difference was observed between control and sham-operated rats. Hypoxia (7% inspired O2) caused hyperventilation and hypothermia in both control (from 541.62 ± 35.02 to 1816.18 ± 170.7 and 36.3 ± 0.12 to 34.4 ± 0.09, respectively) and LC-lesioned rats (LCLR) (from 694.65 ± 63.17 to 2670.29 ± 471.33 and 36 ± 0.12 to 35.3 ± 0.12, respectively), but the increase in VE was higher (P<0.05) and hypothermia was reduced (P<0.05) in LCLR. L-NAME caused no significant change in VE or in body temperature under normoxia, but abolished both the hypoxia-induced hyperventilation and hypothermia. Hypoxia-induced hyperventilation was reduced in LCLR treated with L-NAME. L-NAME also abolished the hypoxia-induced hypothermia in LCLR. The present data indicate that hypoxia-induced hyperventilation and hypothermia may be related to the LC, and that NO is involved in these responses.
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spelling Role of nitric oxide in hypoxia-induced hyperventilation and hypothermia: participation of the locus coeruleusnitric oxidelocus coeruleushypoxiaventilationbody temperatureratHypoxia elicits hyperventilation and hypothermia, but the mechanisms involved are not well understood. The nitric oxide (NO) pathway is involved in hypoxia-induced hypothermia and hyperventilation, and works as a neuromodulator in the central nervous system, including the locus coeruleus (LC), which is a noradrenergic nucleus in the pons. The LC plays a role in a number of stress-induced responses, but its participation in the control of breathing and thermoregulation is unclear. Thus, in the present study, we tested the hypothesis that LC plays a role in the hypoxia-induced hypothermia and hyperventilation, and that NO is involved in these responses. Electrolytic lesions were performed bilaterally within the LC in awake unrestrained adult male Wistar rats weighing 250-350 g. Body temperature and pulmonary ventilation (VE) were measured. The rats were divided into 3 groups: control (N = 16), sham operated (N = 7) and LC lesioned (N = 19), and each group received a saline or an NG-nitro-L-arginine methyl ester (L-NAME, 250 µg/µl) intracerebroventricular (icv) injection. No significant difference was observed between control and sham-operated rats. Hypoxia (7% inspired O2) caused hyperventilation and hypothermia in both control (from 541.62 ± 35.02 to 1816.18 ± 170.7 and 36.3 ± 0.12 to 34.4 ± 0.09, respectively) and LC-lesioned rats (LCLR) (from 694.65 ± 63.17 to 2670.29 ± 471.33 and 36 ± 0.12 to 35.3 ± 0.12, respectively), but the increase in VE was higher (P<0.05) and hypothermia was reduced (P<0.05) in LCLR. L-NAME caused no significant change in VE or in body temperature under normoxia, but abolished both the hypoxia-induced hyperventilation and hypothermia. Hypoxia-induced hyperventilation was reduced in LCLR treated with L-NAME. L-NAME also abolished the hypoxia-induced hypothermia in LCLR. The present data indicate that hypoxia-induced hyperventilation and hypothermia may be related to the LC, and that NO is involved in these responses.Associação Brasileira de Divulgação Científica1999-11-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999001100009Brazilian Journal of Medical and Biological Research v.32 n.11 1999reponame:Brazilian Journal of Medical and Biological Researchinstname:Associação Brasileira de Divulgação Científica (ABDC)instacron:ABDC10.1590/S0100-879X1999001100009info:eu-repo/semantics/openAccessFabris,G.Anselmo-Franci,J.A.Branco,L.G.S.eng1999-11-11T00:00:00Zoai:scielo:S0100-879X1999001100009Revistahttps://www.bjournal.org/https://old.scielo.br/oai/scielo-oai.phpbjournal@terra.com.br||bjournal@terra.com.br1414-431X0100-879Xopendoar:1999-11-11T00:00Brazilian Journal of Medical and Biological Research - Associação Brasileira de Divulgação Científica (ABDC)false
dc.title.none.fl_str_mv Role of nitric oxide in hypoxia-induced hyperventilation and hypothermia: participation of the locus coeruleus
title Role of nitric oxide in hypoxia-induced hyperventilation and hypothermia: participation of the locus coeruleus
spellingShingle Role of nitric oxide in hypoxia-induced hyperventilation and hypothermia: participation of the locus coeruleus
Fabris,G.
nitric oxide
locus coeruleus
hypoxia
ventilation
body temperature
rat
title_short Role of nitric oxide in hypoxia-induced hyperventilation and hypothermia: participation of the locus coeruleus
title_full Role of nitric oxide in hypoxia-induced hyperventilation and hypothermia: participation of the locus coeruleus
title_fullStr Role of nitric oxide in hypoxia-induced hyperventilation and hypothermia: participation of the locus coeruleus
title_full_unstemmed Role of nitric oxide in hypoxia-induced hyperventilation and hypothermia: participation of the locus coeruleus
title_sort Role of nitric oxide in hypoxia-induced hyperventilation and hypothermia: participation of the locus coeruleus
author Fabris,G.
author_facet Fabris,G.
Anselmo-Franci,J.A.
Branco,L.G.S.
author_role author
author2 Anselmo-Franci,J.A.
Branco,L.G.S.
author2_role author
author
dc.contributor.author.fl_str_mv Fabris,G.
Anselmo-Franci,J.A.
Branco,L.G.S.
dc.subject.por.fl_str_mv nitric oxide
locus coeruleus
hypoxia
ventilation
body temperature
rat
topic nitric oxide
locus coeruleus
hypoxia
ventilation
body temperature
rat
description Hypoxia elicits hyperventilation and hypothermia, but the mechanisms involved are not well understood. The nitric oxide (NO) pathway is involved in hypoxia-induced hypothermia and hyperventilation, and works as a neuromodulator in the central nervous system, including the locus coeruleus (LC), which is a noradrenergic nucleus in the pons. The LC plays a role in a number of stress-induced responses, but its participation in the control of breathing and thermoregulation is unclear. Thus, in the present study, we tested the hypothesis that LC plays a role in the hypoxia-induced hypothermia and hyperventilation, and that NO is involved in these responses. Electrolytic lesions were performed bilaterally within the LC in awake unrestrained adult male Wistar rats weighing 250-350 g. Body temperature and pulmonary ventilation (VE) were measured. The rats were divided into 3 groups: control (N = 16), sham operated (N = 7) and LC lesioned (N = 19), and each group received a saline or an NG-nitro-L-arginine methyl ester (L-NAME, 250 µg/µl) intracerebroventricular (icv) injection. No significant difference was observed between control and sham-operated rats. Hypoxia (7% inspired O2) caused hyperventilation and hypothermia in both control (from 541.62 ± 35.02 to 1816.18 ± 170.7 and 36.3 ± 0.12 to 34.4 ± 0.09, respectively) and LC-lesioned rats (LCLR) (from 694.65 ± 63.17 to 2670.29 ± 471.33 and 36 ± 0.12 to 35.3 ± 0.12, respectively), but the increase in VE was higher (P<0.05) and hypothermia was reduced (P<0.05) in LCLR. L-NAME caused no significant change in VE or in body temperature under normoxia, but abolished both the hypoxia-induced hyperventilation and hypothermia. Hypoxia-induced hyperventilation was reduced in LCLR treated with L-NAME. L-NAME also abolished the hypoxia-induced hypothermia in LCLR. The present data indicate that hypoxia-induced hyperventilation and hypothermia may be related to the LC, and that NO is involved in these responses.
publishDate 1999
dc.date.none.fl_str_mv 1999-11-01
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999001100009
url http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999001100009
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv 10.1590/S0100-879X1999001100009
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv text/html
dc.publisher.none.fl_str_mv Associação Brasileira de Divulgação Científica
publisher.none.fl_str_mv Associação Brasileira de Divulgação Científica
dc.source.none.fl_str_mv Brazilian Journal of Medical and Biological Research v.32 n.11 1999
reponame:Brazilian Journal of Medical and Biological Research
instname:Associação Brasileira de Divulgação Científica (ABDC)
instacron:ABDC
instname_str Associação Brasileira de Divulgação Científica (ABDC)
instacron_str ABDC
institution ABDC
reponame_str Brazilian Journal of Medical and Biological Research
collection Brazilian Journal of Medical and Biological Research
repository.name.fl_str_mv Brazilian Journal of Medical and Biological Research - Associação Brasileira de Divulgação Científica (ABDC)
repository.mail.fl_str_mv bjournal@terra.com.br||bjournal@terra.com.br
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