The effects of early post-traumatic hyperthermia in female and ovariectomized rats

Takamoto Suzuki, Helen Bramlett, Gladys Ruenes, W. Dalton Dietrich

Research output: Contribution to journalArticle

40 Citations (Scopus)

Abstract

Episodes of post-traumatic hyperthermia commonly occur in the head-injured patient population. Although post-traumatic hyperthermia has been shown to worsen outcome in experimental studies using male rats, the consequences of secondary hyperthermia following traumatic brain injury (TBI) have not been investigated in female animals. Thus, the purpose of this study was to examine the effects of post-traumatic hyperthermia after fluid-percussion (F-P) brain injury in intact and ovariectomized female rats. Thirty-eight female Sprague-Dawley rats were used in these experiments. Intact female rats underwent TBI followed 30 min later by a 4-h period of normothermia (37°C) or brain hyperthermia (40°C). Female rats that had been ovariectomized 10 days prior to TBI were also traumatized and followed by a period of normothermia or hyperthermia. At 72 h after TBI, rats were perfusion-fixed for quantitative histopathological and immunocytochemical evaluation. Following normothermic TBI, intact female rats demonstrated significantly smaller contusion volumes, decreased frequency of axonal beta-amyloid precursor protein (β-APP) profiles, and greater numbers of NeuN-positive cortical neurons compared to traumatized ovariectomized females. Although post-traumatic hyperthermia increased contusion volume, cortical neuronal cell death and axonal damage in both intact and ovariectomized female groups, the effects of the induced hyperthermic period were more pronounced in ovariectomized animals. These findings demonstrate for the first time that post-traumatic hyperthermia worsens histopathological outcome in female rats, and that neural hormones, including estrogen and progesterone, may protect against secondary hyperthermic insults.

Original languageEnglish
Pages (from-to)842-853
Number of pages12
JournalJournal of Neurotrauma
Volume21
Issue number7
DOIs
StatePublished - Jul 1 2004

Fingerprint

Fever
Percussion
Amyloid beta-Protein Precursor
Contusions
Brain Injuries
Progesterone
Sprague Dawley Rats
Estrogens
Cell Death
Perfusion
Head
Traumatic Brain Injury
Hormones
Neurons
Brain
Population

Keywords

  • Fever
  • Gender
  • Hyperthermia
  • Traumatic brain injury

ASJC Scopus subject areas

  • Clinical Neurology
  • Neuroscience(all)

Cite this

The effects of early post-traumatic hyperthermia in female and ovariectomized rats. / Suzuki, Takamoto; Bramlett, Helen; Ruenes, Gladys; Dalton Dietrich, W.

In: Journal of Neurotrauma, Vol. 21, No. 7, 01.07.2004, p. 842-853.

Research output: Contribution to journalArticle

@article{37427e83bb6546b182915019e645045f,
title = "The effects of early post-traumatic hyperthermia in female and ovariectomized rats",
abstract = "Episodes of post-traumatic hyperthermia commonly occur in the head-injured patient population. Although post-traumatic hyperthermia has been shown to worsen outcome in experimental studies using male rats, the consequences of secondary hyperthermia following traumatic brain injury (TBI) have not been investigated in female animals. Thus, the purpose of this study was to examine the effects of post-traumatic hyperthermia after fluid-percussion (F-P) brain injury in intact and ovariectomized female rats. Thirty-eight female Sprague-Dawley rats were used in these experiments. Intact female rats underwent TBI followed 30 min later by a 4-h period of normothermia (37°C) or brain hyperthermia (40°C). Female rats that had been ovariectomized 10 days prior to TBI were also traumatized and followed by a period of normothermia or hyperthermia. At 72 h after TBI, rats were perfusion-fixed for quantitative histopathological and immunocytochemical evaluation. Following normothermic TBI, intact female rats demonstrated significantly smaller contusion volumes, decreased frequency of axonal beta-amyloid precursor protein (β-APP) profiles, and greater numbers of NeuN-positive cortical neurons compared to traumatized ovariectomized females. Although post-traumatic hyperthermia increased contusion volume, cortical neuronal cell death and axonal damage in both intact and ovariectomized female groups, the effects of the induced hyperthermic period were more pronounced in ovariectomized animals. These findings demonstrate for the first time that post-traumatic hyperthermia worsens histopathological outcome in female rats, and that neural hormones, including estrogen and progesterone, may protect against secondary hyperthermic insults.",
keywords = "Fever, Gender, Hyperthermia, Traumatic brain injury",
author = "Takamoto Suzuki and Helen Bramlett and Gladys Ruenes and {Dalton Dietrich}, W.",
year = "2004",
month = "7",
day = "1",
doi = "10.1089/0897715041526186",
language = "English",
volume = "21",
pages = "842--853",
journal = "Journal of Neurotrauma",
issn = "0897-7151",
publisher = "Mary Ann Liebert Inc.",
number = "7",

}

TY - JOUR

T1 - The effects of early post-traumatic hyperthermia in female and ovariectomized rats

AU - Suzuki, Takamoto

AU - Bramlett, Helen

AU - Ruenes, Gladys

AU - Dalton Dietrich, W.

PY - 2004/7/1

Y1 - 2004/7/1

N2 - Episodes of post-traumatic hyperthermia commonly occur in the head-injured patient population. Although post-traumatic hyperthermia has been shown to worsen outcome in experimental studies using male rats, the consequences of secondary hyperthermia following traumatic brain injury (TBI) have not been investigated in female animals. Thus, the purpose of this study was to examine the effects of post-traumatic hyperthermia after fluid-percussion (F-P) brain injury in intact and ovariectomized female rats. Thirty-eight female Sprague-Dawley rats were used in these experiments. Intact female rats underwent TBI followed 30 min later by a 4-h period of normothermia (37°C) or brain hyperthermia (40°C). Female rats that had been ovariectomized 10 days prior to TBI were also traumatized and followed by a period of normothermia or hyperthermia. At 72 h after TBI, rats were perfusion-fixed for quantitative histopathological and immunocytochemical evaluation. Following normothermic TBI, intact female rats demonstrated significantly smaller contusion volumes, decreased frequency of axonal beta-amyloid precursor protein (β-APP) profiles, and greater numbers of NeuN-positive cortical neurons compared to traumatized ovariectomized females. Although post-traumatic hyperthermia increased contusion volume, cortical neuronal cell death and axonal damage in both intact and ovariectomized female groups, the effects of the induced hyperthermic period were more pronounced in ovariectomized animals. These findings demonstrate for the first time that post-traumatic hyperthermia worsens histopathological outcome in female rats, and that neural hormones, including estrogen and progesterone, may protect against secondary hyperthermic insults.

AB - Episodes of post-traumatic hyperthermia commonly occur in the head-injured patient population. Although post-traumatic hyperthermia has been shown to worsen outcome in experimental studies using male rats, the consequences of secondary hyperthermia following traumatic brain injury (TBI) have not been investigated in female animals. Thus, the purpose of this study was to examine the effects of post-traumatic hyperthermia after fluid-percussion (F-P) brain injury in intact and ovariectomized female rats. Thirty-eight female Sprague-Dawley rats were used in these experiments. Intact female rats underwent TBI followed 30 min later by a 4-h period of normothermia (37°C) or brain hyperthermia (40°C). Female rats that had been ovariectomized 10 days prior to TBI were also traumatized and followed by a period of normothermia or hyperthermia. At 72 h after TBI, rats were perfusion-fixed for quantitative histopathological and immunocytochemical evaluation. Following normothermic TBI, intact female rats demonstrated significantly smaller contusion volumes, decreased frequency of axonal beta-amyloid precursor protein (β-APP) profiles, and greater numbers of NeuN-positive cortical neurons compared to traumatized ovariectomized females. Although post-traumatic hyperthermia increased contusion volume, cortical neuronal cell death and axonal damage in both intact and ovariectomized female groups, the effects of the induced hyperthermic period were more pronounced in ovariectomized animals. These findings demonstrate for the first time that post-traumatic hyperthermia worsens histopathological outcome in female rats, and that neural hormones, including estrogen and progesterone, may protect against secondary hyperthermic insults.

KW - Fever

KW - Gender

KW - Hyperthermia

KW - Traumatic brain injury

UR - http://www.scopus.com/inward/record.url?scp=3242888004&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=3242888004&partnerID=8YFLogxK

U2 - 10.1089/0897715041526186

DO - 10.1089/0897715041526186

M3 - Article

C2 - 15307897

AN - SCOPUS:3242888004

VL - 21

SP - 842

EP - 853

JO - Journal of Neurotrauma

JF - Journal of Neurotrauma

SN - 0897-7151

IS - 7

ER -