Influence of posttraumatic hypoxia on behavioral recovery and histopathological outcome following moderate spinal cord injury in rats

Y. Yanagawa, Alexander Marcillo, R. Garcia-Rojas, K. E. Loor, W. Dalton Dietrich

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

Pulmonary dysfunction leading to secondary hypoxia is a common complication of spinal cord injury (SCI). The purpose of this study was to clarify the behavioral and histopathological consequences of posttraumatic hypoxia in an established model of traumatic SCI. Forty-five female Sprague-Dawley rats were randomly assigned to one of four groups, including (1) laminectomy and normoxia (n = 10), (2) laminectomy and hypoxia (n = 11), (3) NYU weight-drop and normoxia (n = 12), and (4) NYU weight-drop and hypoxia (n = 11). For these studies, a moderate injury was induced by adjusting the height of the weight drop (10 g) to 12.5 mm above the exposed spinal cord (T10). Immediately after injury, PaO2 in the hypoxic rats was kept between 30 and 35 mm Hg for 30 min. PaO2 in the normoxic group was maintained over 100 mm Hg, while PaCO2 in all rats was maintained at 35-40 mm Hg. The behavior of the rats was checked every 7 days using the Basso, Beattie, and Bresnahan (BBB) locomotor rating scale. Rats were sacrificed at 8 weeks for quantitative histopathological analysis of lesion areas. During the hypoxic insults, the mean arterial blood pressure dropped in both sham control and weight-drop rats (p < 0.01). At the end of the 8-week monitoring period, BBB scores were 12.5 ± 3.1 (mean ± SEM) and 14.2 ± 3.4 in the normoxic and hypoxic traumatized rats, respectively. No significant difference between the traumatized groups was documented with BBB monitoring. In contrast, the percent of gray matter necrosis at the impact epicenter was significantly increased in hypoxic versus normoxic SCI rats (p < 0.01). These data demonstrate that posttraumatic hypoxia complicated by mild hypotension aggravates the histopathological consequences of SCI and further emphasize the need to control for secondary hypoxic insults after experimental and clinical SCI. Potential explanations for the lack of a correlation between the behavioral and histopathological findings are discussed.

Original languageEnglish
Pages (from-to)635-644
Number of pages10
JournalJournal of Neurotrauma
Volume18
Issue number6
StatePublished - Jul 4 2001

Fingerprint

Spinal Cord Injuries
Weights and Measures
Laminectomy
Arterial Pressure
Wounds and Injuries
Hypoxia
Hypotension
Sprague Dawley Rats
Spinal Cord
Necrosis
Lung

Keywords

  • Behavior
  • Hypoxia
  • Secondary insults
  • Spinal cord injury

ASJC Scopus subject areas

  • Clinical Neurology
  • Neuroscience(all)

Cite this

Influence of posttraumatic hypoxia on behavioral recovery and histopathological outcome following moderate spinal cord injury in rats. / Yanagawa, Y.; Marcillo, Alexander; Garcia-Rojas, R.; Loor, K. E.; Dalton Dietrich, W.

In: Journal of Neurotrauma, Vol. 18, No. 6, 04.07.2001, p. 635-644.

Research output: Contribution to journalArticle

@article{85cd22a0a3d34ba4ab76bd3595dba4eb,
title = "Influence of posttraumatic hypoxia on behavioral recovery and histopathological outcome following moderate spinal cord injury in rats",
abstract = "Pulmonary dysfunction leading to secondary hypoxia is a common complication of spinal cord injury (SCI). The purpose of this study was to clarify the behavioral and histopathological consequences of posttraumatic hypoxia in an established model of traumatic SCI. Forty-five female Sprague-Dawley rats were randomly assigned to one of four groups, including (1) laminectomy and normoxia (n = 10), (2) laminectomy and hypoxia (n = 11), (3) NYU weight-drop and normoxia (n = 12), and (4) NYU weight-drop and hypoxia (n = 11). For these studies, a moderate injury was induced by adjusting the height of the weight drop (10 g) to 12.5 mm above the exposed spinal cord (T10). Immediately after injury, PaO2 in the hypoxic rats was kept between 30 and 35 mm Hg for 30 min. PaO2 in the normoxic group was maintained over 100 mm Hg, while PaCO2 in all rats was maintained at 35-40 mm Hg. The behavior of the rats was checked every 7 days using the Basso, Beattie, and Bresnahan (BBB) locomotor rating scale. Rats were sacrificed at 8 weeks for quantitative histopathological analysis of lesion areas. During the hypoxic insults, the mean arterial blood pressure dropped in both sham control and weight-drop rats (p < 0.01). At the end of the 8-week monitoring period, BBB scores were 12.5 ± 3.1 (mean ± SEM) and 14.2 ± 3.4 in the normoxic and hypoxic traumatized rats, respectively. No significant difference between the traumatized groups was documented with BBB monitoring. In contrast, the percent of gray matter necrosis at the impact epicenter was significantly increased in hypoxic versus normoxic SCI rats (p < 0.01). These data demonstrate that posttraumatic hypoxia complicated by mild hypotension aggravates the histopathological consequences of SCI and further emphasize the need to control for secondary hypoxic insults after experimental and clinical SCI. Potential explanations for the lack of a correlation between the behavioral and histopathological findings are discussed.",
keywords = "Behavior, Hypoxia, Secondary insults, Spinal cord injury",
author = "Y. Yanagawa and Alexander Marcillo and R. Garcia-Rojas and Loor, {K. E.} and {Dalton Dietrich}, W.",
year = "2001",
month = "7",
day = "4",
language = "English",
volume = "18",
pages = "635--644",
journal = "Journal of Neurotrauma",
issn = "0897-7151",
publisher = "Mary Ann Liebert Inc.",
number = "6",

}

TY - JOUR

T1 - Influence of posttraumatic hypoxia on behavioral recovery and histopathological outcome following moderate spinal cord injury in rats

AU - Yanagawa, Y.

AU - Marcillo, Alexander

AU - Garcia-Rojas, R.

AU - Loor, K. E.

AU - Dalton Dietrich, W.

PY - 2001/7/4

Y1 - 2001/7/4

N2 - Pulmonary dysfunction leading to secondary hypoxia is a common complication of spinal cord injury (SCI). The purpose of this study was to clarify the behavioral and histopathological consequences of posttraumatic hypoxia in an established model of traumatic SCI. Forty-five female Sprague-Dawley rats were randomly assigned to one of four groups, including (1) laminectomy and normoxia (n = 10), (2) laminectomy and hypoxia (n = 11), (3) NYU weight-drop and normoxia (n = 12), and (4) NYU weight-drop and hypoxia (n = 11). For these studies, a moderate injury was induced by adjusting the height of the weight drop (10 g) to 12.5 mm above the exposed spinal cord (T10). Immediately after injury, PaO2 in the hypoxic rats was kept between 30 and 35 mm Hg for 30 min. PaO2 in the normoxic group was maintained over 100 mm Hg, while PaCO2 in all rats was maintained at 35-40 mm Hg. The behavior of the rats was checked every 7 days using the Basso, Beattie, and Bresnahan (BBB) locomotor rating scale. Rats were sacrificed at 8 weeks for quantitative histopathological analysis of lesion areas. During the hypoxic insults, the mean arterial blood pressure dropped in both sham control and weight-drop rats (p < 0.01). At the end of the 8-week monitoring period, BBB scores were 12.5 ± 3.1 (mean ± SEM) and 14.2 ± 3.4 in the normoxic and hypoxic traumatized rats, respectively. No significant difference between the traumatized groups was documented with BBB monitoring. In contrast, the percent of gray matter necrosis at the impact epicenter was significantly increased in hypoxic versus normoxic SCI rats (p < 0.01). These data demonstrate that posttraumatic hypoxia complicated by mild hypotension aggravates the histopathological consequences of SCI and further emphasize the need to control for secondary hypoxic insults after experimental and clinical SCI. Potential explanations for the lack of a correlation between the behavioral and histopathological findings are discussed.

AB - Pulmonary dysfunction leading to secondary hypoxia is a common complication of spinal cord injury (SCI). The purpose of this study was to clarify the behavioral and histopathological consequences of posttraumatic hypoxia in an established model of traumatic SCI. Forty-five female Sprague-Dawley rats were randomly assigned to one of four groups, including (1) laminectomy and normoxia (n = 10), (2) laminectomy and hypoxia (n = 11), (3) NYU weight-drop and normoxia (n = 12), and (4) NYU weight-drop and hypoxia (n = 11). For these studies, a moderate injury was induced by adjusting the height of the weight drop (10 g) to 12.5 mm above the exposed spinal cord (T10). Immediately after injury, PaO2 in the hypoxic rats was kept between 30 and 35 mm Hg for 30 min. PaO2 in the normoxic group was maintained over 100 mm Hg, while PaCO2 in all rats was maintained at 35-40 mm Hg. The behavior of the rats was checked every 7 days using the Basso, Beattie, and Bresnahan (BBB) locomotor rating scale. Rats were sacrificed at 8 weeks for quantitative histopathological analysis of lesion areas. During the hypoxic insults, the mean arterial blood pressure dropped in both sham control and weight-drop rats (p < 0.01). At the end of the 8-week monitoring period, BBB scores were 12.5 ± 3.1 (mean ± SEM) and 14.2 ± 3.4 in the normoxic and hypoxic traumatized rats, respectively. No significant difference between the traumatized groups was documented with BBB monitoring. In contrast, the percent of gray matter necrosis at the impact epicenter was significantly increased in hypoxic versus normoxic SCI rats (p < 0.01). These data demonstrate that posttraumatic hypoxia complicated by mild hypotension aggravates the histopathological consequences of SCI and further emphasize the need to control for secondary hypoxic insults after experimental and clinical SCI. Potential explanations for the lack of a correlation between the behavioral and histopathological findings are discussed.

KW - Behavior

KW - Hypoxia

KW - Secondary insults

KW - Spinal cord injury

UR - http://www.scopus.com/inward/record.url?scp=0034971032&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0034971032&partnerID=8YFLogxK

M3 - Article

C2 - 11437086

AN - SCOPUS:0034971032

VL - 18

SP - 635

EP - 644

JO - Journal of Neurotrauma

JF - Journal of Neurotrauma

SN - 0897-7151

IS - 6

ER -