The effect of glutamine on cerebral ischaemic injury after cardiac arrest.

Abstract

The aim of this study is to investigate whether glutamine (GLN) enhances heat shock protein-25 (Hsp-25) and heat shock protein-72 (Hsp-72) expressions and attenuates cerebral ischaemic injury in rat cardiac arrest model. Rats survived from cardiac arrest model were randomly assigned to CPR+GLN group (0.75 g/kg of alanyl-glutamine, n=6) or CPR group (same volume of 0.9% saline, n=6). Additional 6 rats were used for SHAM group. For the outcome measures, neurologic deficit score (NDS, 0-80) was checked at 24h and 72 h after cardiac arrest. At 72 h after cardiac arrest, rats were euthanised and the brain was harvested. Then, right hemisphere was used for cresyl-violet and TUNEL staining. Left hemisphere was used for Western blot analysis of phosphorylated heat shock factor-1 (p-HSF-1), Hsp-25, Hsp-72, and cleaved caspase-3. Kruskal-Wallis test and Mann-Whitney U post hoc test with Bonferroni correction were used for the analysis. Resuscitation variables were not different between CPR and CPR+GLN. NDS in CPR+GLN was higher than that in CPR (p<0.017) and lower than that in SHAM (p<0.017) at both 24h and 72 h. p-HSF-1, Hsp-25 and Hsp-72 expressions in CPR+GLN were significantly enhanced (p<0.017) than those in other groups. Cleaved caspase-3 expression in CPR was significantly higher (p<0.017) than in SHAM and CPR+GLN. Ischaemic and TUNEL-positive neurons were more frequently observed in CPR than in CPR+GLN. Glutamine attenuates cerebral ischaemic injury in cardiac arrest model of rats and this is associated with the enhancement of Hsp-25 and Hsp-72 expressions.