ABSTRACT
Objective To explore the feasibility of mechanical chest compression to establish a rat model of car?diopulmonary resuscitation ( CPR) . Methods 4?month old healthy male Sprague Dawley rats were randomly divided into control group ( n=6 ) and model group ( n=10 ) . After induction of anaesthesia with 10% chloraldurate ( 3 ml/kg, i. p. ) , tracheal intubation and left femoral artery cannulation were performed. Under electrocardiographic and artery blood pressure monitoring, tracheal obstruction ( TO) was performed to rats in model group. At 2 min after the cardiac arrest ( CA) occurred, CPRs were administered to the rats using a self?made animal chest compressor, which provided chest?com?pression at a rate of 200 bpm. Results Shortly after TO, rats in the model group had respiratory arrest, cyanosis and ar?rhythmia. Electrocardiography indicated that CA occurred within 4-5 min, with a decreased artery systolic blood pressure ( <40 mmHg) and a zero pulse pressure. Return of spontaneous circulation ( ROSC) after the CPR was successfully a?chieved in 8 rats (80%), with a transient reperfusion arrhythmia. Finally, 60% of the rats (n=6) recovered to con?sciousness and survived for 24 hrs. The serum biochemical analysis indicated that there were electrolyte disturbances, aci?dosis, impaired renal functions and increased myocardial enzyme spectrum. Pathological examination revealed cardiac rhab? domyolysis, no?reflow phenomenon in renal glomeruli, decrease of neurons and pulmonary congestion in the model group rats. Conclusions Mechanical chest compression can provide minimal cardiac output for the requirement of CPR incardiac arrestin rats. It is feasible to establish rat CPR model with the mechanical chest compression.
ABSTRACT
Objective To investigate the effect of xenon intervention on delayed neuropsychologic sequelae (DNS)in acute carbon monoxide(CO)poisoning.Method Adult Wistar rats were randomly divided into sustained group,early intervention group,and control group.CO(150 ml/kg)was infused by intraperitoneal injection to produce DNS model.In sustained intervention group(S-group),xenon(150 ml/kg/d)was infilsed by intraperitoneal injection for 2 weeks;in control group(C-group),xenon was replaced by equal volume air;and in early intervention group(E-tvoup),xenon(150 ml/kg/d)was,employed in the first 3 days and air(150 ml/kg/d)was substituted for xenon in the following days until 2 weeks after CO poisoning.Morris maze test was used to evaluate the intelligence of rats.The long-term potentiation(LTP)of hippocampus Was detected by neuroelectricity recording.The apoptosis rates in brain was detected by TUNEL staining.The data were expressed as(x±s)and analyzed with student's test and analysis of variance.A P value less than 0.05 indicated statisfical significance.Results After exposure to CO,poisoned rats showed intelligence decline,demyeliation ofwater matler and cell apoptosis increased,which were consistent with DNS.In S-group and E-group,the rates of DNS and apoptosis were significantly lower than those in C-group,whereas the rote of LTP in S-group and E-group Was significantly higher than those in C-group.Conclusions Early xenon intervention can effectively decrease the rates of DNS occurred after acute CO poisoning.