Effects of mild hypothermia on the ROS and expressionof caspase-3 mRNA and LC3 of hippocampus nervecells in rats after cardiopulmonary resuscitation

摘要

BACKGROUND： Cardiac arrest （CA） is a common and serious event in emergency medicine.Despite recent improvements in resuscitation techniques, the survival rate of patients with CA isunchanged. The present study was undertaken to observe the effect of mild hypothermia （MH） on thereactive oxygen species （ROS） and the effect of neurological function and related mechanisms.METHODS： Sixty-five healthy male Sprague Dawley （SD） adult rats were randomly （randomnumber） divided into 2 groups： blank control group （n=5） and CPR group （n=60）. CA was induced byasphyxia. The surviving rats were randomly （random number） divided into two groups： normothermiaCPR group （NT） and hypothermia CPR group （HT）. Normothermia of 37 °C was maintained in theNT group after return of spontaneous circulation （ROSC）, hypothermal intervention of 32 °C wascarried out in the HT group for 4 hours immediately after ROSC. Both the NT and HT groups werethen randomly divided into 2 subgroups 12 hours and 24 hours after ROSC （NT-12, NT-24, HT-12,HT-24 subgroups）. During observation, the neurological defi cit scores （NDSs） was recorded, then thebilateral hippocampi were obtained from rats＇ head, and monoplast suspension of fresh hippocampustissue was made immediately to determine the level of intracellular ROS by flow cytometry.Transmission electron microscope was used to observe the ultramicro changes of cellular nucleus andmitochondria. Reverse transcription-polymerase chain reaction （RT-PCR） was used to determine theexpression of caspase-3 mRNA, and western-blotting （WB） was used to determine the level of LC3in frozen hippocampus tissue. Measured data were analyzed with paired sample t test and One-WayANOVA.