Cargando…

Angiotensin II system in the nucleus tractus solitarii contributes to autonomic dysreflexia in rats with spinal cord injury

BACKGROUND: Autonomic dysreflexia (AD) is a potentially life-threating complication after spinal cord injury (SCI), characterized by episodic hypertension induced by colon or bladder distension. The objective of this study was to determine the role of impaired baroreflex regulation by the nucleus tr...

Descripción completa

Detalles Bibliográficos
Autores principales: Wang, Kai, Duan, Shaoxia, Wen, Xueping, Wang, Weizhong, Fang, Shangping, Qi, Dunyi, Huan, Xiang, Wang, Liwei, He, Zhenzhou
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5524360/
https://www.ncbi.nlm.nih.gov/pubmed/28742157
http://dx.doi.org/10.1371/journal.pone.0181495
_version_ 1783252454480019456
author Wang, Kai
Duan, Shaoxia
Wen, Xueping
Wang, Weizhong
Fang, Shangping
Qi, Dunyi
Huan, Xiang
Wang, Liwei
He, Zhenzhou
author_facet Wang, Kai
Duan, Shaoxia
Wen, Xueping
Wang, Weizhong
Fang, Shangping
Qi, Dunyi
Huan, Xiang
Wang, Liwei
He, Zhenzhou
author_sort Wang, Kai
collection PubMed
description BACKGROUND: Autonomic dysreflexia (AD) is a potentially life-threating complication after spinal cord injury (SCI), characterized by episodic hypertension induced by colon or bladder distension. The objective of this study was to determine the role of impaired baroreflex regulation by the nucleus tractus solitarii(NTS) in the occurrence of AD in a rat model. METHODS: T4 spinal cord transection animal model was used in this study, which included 40 Male rats Colorectal distension (CD) was performed to assess AD and compare the changes of BP, HR, and BRS, six weeks after operation. After that, SCI rats with successfully induced AD were selected. Losartan was microinjected into NTS in SCI rats, then 10, 30, 60 minutes later, CD was performed to calculate the changes of BP, HR, and BRS in order to explicit whether Ang II system was involved in the AD occurrence. Ang II was then Intra-cerebroventricular infused in sham operation rats with CD to mimic the activation of Ang II system in AD. Finally, the level of Ang II in NTS and colocalization of AT1R and NMDA receptor within the NTS neurons were also detected in SCI rats. RESULTS: Compared with sham operation, SCI significantly aggravated the elevation of blood pressure (BP) and impaired baroreflex sensitivity (BRS) induced by colorectal distension; both of which were significantly improved by microinjection of the angiotensin receptor type I (AT(1)R) antagonist losartan into the NTS. Level of angiotensin II (Ang II) in the NTS was significantly increased in the SCI rats than sham. Intracerebroventricular infusion of Ang II also mimicked changes in BP and BRS induced by colorectal distension. Blockade of baroreflex by sinoaortic denervation prevented beneficial effect of losartan on AD. CONCLUSION: We concluded that the activation of Ang II system in NTS may impair blood pressure baroreflex, and contribute to AD after SCI.
format Online
Article
Text
id pubmed-5524360
institution National Center for Biotechnology Information
language English
publishDate 2017
publisher Public Library of Science
record_format MEDLINE/PubMed
spelling pubmed-55243602017-08-07 Angiotensin II system in the nucleus tractus solitarii contributes to autonomic dysreflexia in rats with spinal cord injury Wang, Kai Duan, Shaoxia Wen, Xueping Wang, Weizhong Fang, Shangping Qi, Dunyi Huan, Xiang Wang, Liwei He, Zhenzhou PLoS One Research Article BACKGROUND: Autonomic dysreflexia (AD) is a potentially life-threating complication after spinal cord injury (SCI), characterized by episodic hypertension induced by colon or bladder distension. The objective of this study was to determine the role of impaired baroreflex regulation by the nucleus tractus solitarii(NTS) in the occurrence of AD in a rat model. METHODS: T4 spinal cord transection animal model was used in this study, which included 40 Male rats Colorectal distension (CD) was performed to assess AD and compare the changes of BP, HR, and BRS, six weeks after operation. After that, SCI rats with successfully induced AD were selected. Losartan was microinjected into NTS in SCI rats, then 10, 30, 60 minutes later, CD was performed to calculate the changes of BP, HR, and BRS in order to explicit whether Ang II system was involved in the AD occurrence. Ang II was then Intra-cerebroventricular infused in sham operation rats with CD to mimic the activation of Ang II system in AD. Finally, the level of Ang II in NTS and colocalization of AT1R and NMDA receptor within the NTS neurons were also detected in SCI rats. RESULTS: Compared with sham operation, SCI significantly aggravated the elevation of blood pressure (BP) and impaired baroreflex sensitivity (BRS) induced by colorectal distension; both of which were significantly improved by microinjection of the angiotensin receptor type I (AT(1)R) antagonist losartan into the NTS. Level of angiotensin II (Ang II) in the NTS was significantly increased in the SCI rats than sham. Intracerebroventricular infusion of Ang II also mimicked changes in BP and BRS induced by colorectal distension. Blockade of baroreflex by sinoaortic denervation prevented beneficial effect of losartan on AD. CONCLUSION: We concluded that the activation of Ang II system in NTS may impair blood pressure baroreflex, and contribute to AD after SCI. Public Library of Science 2017-07-24 /pmc/articles/PMC5524360/ /pubmed/28742157 http://dx.doi.org/10.1371/journal.pone.0181495 Text en © 2017 Wang et al http://creativecommons.org/licenses/by/4.0/ 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 author and source are credited.
spellingShingle Research Article
Wang, Kai
Duan, Shaoxia
Wen, Xueping
Wang, Weizhong
Fang, Shangping
Qi, Dunyi
Huan, Xiang
Wang, Liwei
He, Zhenzhou
Angiotensin II system in the nucleus tractus solitarii contributes to autonomic dysreflexia in rats with spinal cord injury
title Angiotensin II system in the nucleus tractus solitarii contributes to autonomic dysreflexia in rats with spinal cord injury
title_full Angiotensin II system in the nucleus tractus solitarii contributes to autonomic dysreflexia in rats with spinal cord injury
title_fullStr Angiotensin II system in the nucleus tractus solitarii contributes to autonomic dysreflexia in rats with spinal cord injury
title_full_unstemmed Angiotensin II system in the nucleus tractus solitarii contributes to autonomic dysreflexia in rats with spinal cord injury
title_short Angiotensin II system in the nucleus tractus solitarii contributes to autonomic dysreflexia in rats with spinal cord injury
title_sort angiotensin ii system in the nucleus tractus solitarii contributes to autonomic dysreflexia in rats with spinal cord injury
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5524360/
https://www.ncbi.nlm.nih.gov/pubmed/28742157
http://dx.doi.org/10.1371/journal.pone.0181495
work_keys_str_mv AT wangkai angiotensiniisysteminthenucleustractussolitariicontributestoautonomicdysreflexiainratswithspinalcordinjury
AT duanshaoxia angiotensiniisysteminthenucleustractussolitariicontributestoautonomicdysreflexiainratswithspinalcordinjury
AT wenxueping angiotensiniisysteminthenucleustractussolitariicontributestoautonomicdysreflexiainratswithspinalcordinjury
AT wangweizhong angiotensiniisysteminthenucleustractussolitariicontributestoautonomicdysreflexiainratswithspinalcordinjury
AT fangshangping angiotensiniisysteminthenucleustractussolitariicontributestoautonomicdysreflexiainratswithspinalcordinjury
AT qidunyi angiotensiniisysteminthenucleustractussolitariicontributestoautonomicdysreflexiainratswithspinalcordinjury
AT huanxiang angiotensiniisysteminthenucleustractussolitariicontributestoautonomicdysreflexiainratswithspinalcordinjury
AT wangliwei angiotensiniisysteminthenucleustractussolitariicontributestoautonomicdysreflexiainratswithspinalcordinjury
AT hezhenzhou angiotensiniisysteminthenucleustractussolitariicontributestoautonomicdysreflexiainratswithspinalcordinjury