Regional distribution of brain interleukin-1β and tumor necrosis factor-α during and after middle cerebral artery occlusion in rats

John Kuluz, Charles Schleien, En Xu, W. Dalton Dietrich, John R Bethea

Research output: Contribution to journalArticlepeer-review

Abstract

Introduction: We have previously described a robust thermoregulatory response to middle cerebral artery occlusion (MCAO) in rats which results in both brain and body hyperthermia. Interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) are pro-inflammatory cytokines and potent endogenous pyrogens which also play a role in the pathogenesis of cerebral ischemia-reperfusion injury. The present study was designed to determine the regional distribution of IL-1β and TNF-α in the brain during and after MCAO in rats. Methods: Fasted adult male rats underwent MCAO (intraluminal suture method) for up to 2h and up to 3h reperfusion. Rectal temperature was measured by thermocouple. Regional distribution of IL-1β and TNF-α was assessed by immunocytochemistry, and brain concentration was measured by ELISA in 3-4 rats at the following time points: 1h and 2h MCAO, and 1h and 3h reperfusion after 2h MCAO. Plasma concentration of IL-1β and TNF-α was measured by ELISA at baseline and at sacrifice. Data (mean ±SEM) were analyzed by ANOVA and Kruskal-Wallis (*p<0.05). Results: Rectal temperature increased from 37.2±0.1°C at baseline to 38.6±0.1* and 39.1±0.2°C* at 1h and 2h MCAO, then decreased to 38.5±0.3°C* at 3h reperfusion. IL-1β and TNF-α were not detected in plasma at any time point Expression of TNF-α was greater than that of IL-1β in the cortex and striatum during MCAO and early reperfusion. * However, in the preoptic area of the hypothalamus immunostaining for IL-1β appeared to be greater than that for TNF-α and was not limited to the ischemic hemisphere. Conclusions: These preliminary data suggest that TNF-α is more involved than IL-1β in early cerebral ischemia-reperfusion events, whereas IL-1β may play a greater role in the development of hyperthermia during MCAO in rats.

Original languageEnglish (US)
Pages (from-to)A132
JournalCritical care medicine
Volume27
Issue number1 SUPPL.
StatePublished - Dec 1 1999

ASJC Scopus subject areas

  • Critical Care and Intensive Care Medicine

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