Modulation of nuclear factor-kappaB activation and decreased markers of neurological injury associated with hypothermic therapy in experimental bacterial meningitis.
Crit Care Med 2002;
30:2553-9. [PMID:
12441769 DOI:
10.1097/00003246-200211000-00025]
[Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE
This study was designed to evaluate the use of moderate hypothermia in a model of meningitis-induced brain injury and its effect on the activation of nuclear factor-kappaB, biological markers of neuronal injury, and neurobehavioral performance.
DESIGN
Randomized, prospective animal study.
SETTING
University research laboratory.
SUBJECTS
Male Wistar rats.
INTERVENTIONS
Animals underwent a basilar cistern tap receiving either sterile saline as a placebo or an equivalent volume of a group B streptococcal suspension. Sixteen hours after inoculation, animals were stratified by their clinical severity score, were randomized to either hypothermic (32-34 degrees C) or normothermic (37-39 degrees C) conditions, and received antibiotics. Hypothermic animals were kept under these temperature conditions for 6 hrs before rewarming. Two protocols were used. For the first protocol, changes in nuclear factor-kappaB activation and heat shock protein induction at 24 hrs and 48 hrs after inoculation were evaluated. In the second protocol, serum C-tau concentrations at 5 days and neurobehavioral performances at 3 wks were assessed.
MEASUREMENTS AND MAIN RESULTS
Meningitis triggered a >50% increase in cerebral nuclear factor-kappaB activation. The addition of a 6-hr period of hypothermia reduced nuclear factor-kappaB activation by 32% when measured at the end of the hypothermic period. At 48 hrs, this decrease in nuclear factor-kappaB activation was no longer apparent, but there was a significant decrease in the heat shock response. Serum C-tau concentrations at 5 days postinjury, a biomarker of brain injury, were reduced by 69% in hypothermic treated animals. Furthermore, hypothermia reduced the brain water content of infected animals. However, hypothermia did not improve the animals' neurobehavioral performance.
CONCLUSION
The findings from this study suggest that hypothermia produces a transitory attenuation of nuclear factor-kappaB activation in meningitic brain injury and improvement in some biomarkers of neuronal injury. The consequence of intermittent suppression of nuclear factor-kappaB activation by inducing specific periods of hypothermia requires further study.
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