ABSTRACT
Objective To investigate the safety and therapeutic effect of intra-carotid infusion with cold sa line in rats with acute focal cerebral ischemia-reperfusion injury.Methods 60 rats were randomly divided into six groups:sham operated group,normal infusion group,stroke group,local hypothermic group,local normothermic group,and systemic infusion group.Brain infarct volume and cerebral water content were analyzed 48 h after ischemia.Neurological deficits were assessed using the mNSS 24 h and 48 h after infarction.Results In the local hypothermic group,brain temperature was reduced to 33 to 34 ℃ within 5 to 10 minutes,and this significantly low temperature maintained to nearly 60 minutes after infusion continued.Physiological variables were not significantly different among each time point (P ＞ 0.05).No significant morphological abnormality was found in brain sections stained with TTC and HE.Animals receiving local cold infusion significantly decreased infarct volume and brain water content compared to stroke group (P ＜ 0.05).Both 24 h and 48 h mNSS in local hypothermic group was significantly lower than those in other groups (P ＜ 0.05).Conclusions Intra-carotid infusion with cold saline can quickly and effectively reduce brain temperature and is a relatively safe cooling method.Local hypothermia significantly reduced brain infarct volume,decreased brain water content and improved neurological functional outcomes after brain ischemia.
ABSTRACT
<p><b>OBJECTIVE</b>To compare the neuroprotective effects of intracarotid cold saline infusion (ICSI), ice cap and systemic cooling in rats with early cerebral ischemia.</p><p><b>METHODS</b>SD rats were randomly divided into model group, ice cap group, systemic cooling group and ICSI group (n=13). Cerebral ischemia was induced by middle cerebral artery occlusion (MCAO) for 2 h. In the 3 hypothermic groups, the target temperature of 33-34 degrees celsius; was achieved and maintained for 20 min. In each group, the neurological scores were recorded at 48 h after the reperfusion, and the brains were removed for measuring the infarct size using 2,3,5-triphenyltetrazolium chloride staining. The brain water contents and serum levels of neuron-specific enolase (NSE), S100β and matrix metalloproteinase 9 (MMP9) were also measured.</p><p><b>RESULTS</b>Compared with the model group, the ice cap, systemic cooling and ICSI groups all showed significantly reduced infarct size by 27.4% (P<0.05), 47.6% (P<0.01) and 61.6% (P<0.01), respectively. The systemic cooling and ICSI groups, but not the ice cap group, had significantly lower brain water contents than the model group (P<0.05). Among the 3 hypothermic methods, only ICSI significantly improved the neurological scores (P<0.05) and reduced serum NSE and S100β levels (P<0.05).</p><p><b>CONCLUSION</b>Of the 3 hypothermic groups, ICSI has the best neuroprotective effects, and systemic cooling produces better effect than ice cap in rats with ischemic stroke.</p>