| Objective To investigate effect of the inducible nitric oxide synthase (iNOS) inhibitor on brain tissue after cardiac arrest (SCA) of the rats.Methods 90 Sprague-Dawley rats were divided into to 3 groups without sex consideration:sham operation group(A), control group(B), and interventiongroup (C),and each group was divided into 5 subgroups according to 6h,12h,24h,48h,72h time point with 6 rats in each subgroup. Group A was only given organ intubation and femoral vein catheter, Group B and C were made to asphyxia cardiac arrest model, group C was given rapid intravenous injection of 0.2mg/ml/kg iNOS inhibitors immediately after resusciation. Change of mean arterial pressure (MAP) was measured within 60 minutes in group A after operation and group B and C after after restoration of spontaneous circulation (ROSC). Venous blood concentrations of serum CKBB in each group was detected at each time point. Rats were sacrificed at each time point, The brains were taken out for examination of water content, expression of iNOS and NO of the brains as well as analyses of brain pathology changes, MAP was monitored within 60 minutes in group A after the operation was successful set and brain was detected simultaneously at B, C time points. Quantitative data were expressed as mean±standard deviation (x±s). SPSS 17.0 software was applied for One-way analysis of variance (ANOVA). Statistical differences were considered significant when p< 0.05.Results①MAP changes, there were no significant difference of MAP changes beetween groups (P> 0.05).②CKBB concentrations:There was not statistically difference of CKBB concentrations in group A at different time points (P> 0.05). Group B and C increased greater compared with group A (P<0.01), However Group C decreased significantly compared with group B at each time point with (P <0.01). CKBB concentration began to increase at 6h after resuscitation, and reached the peak at 24h, but began to decline at 48 hour.③NO of brain tissue:NO increased in group B and C compared with group A (P<0.01), not statistically significant were found in group A at different time points (P> 0.05). Group C decreased at each time point compared with group B (P<0.01 or P<0.05). NO began to increase at 6h after resuscitation, reaching the peak at 24h, however started to decline at 48 hour.④iNOS positive brain tissue cells:There was no significant difference at different time points in group A (P> 0.05). Group B and C had a higher expression of iNOS than Group A (P<0.01), with a less degree in group C (P<0.01). iNOS positive cells of brain tissue began to increase at 6h after resuscitation, reaching the peak at 24h, however begin to decline at 48 hours. The changes was relevant to NO changes.⑤Water content of brain tissue:There was not statistically difference in group A at different time points (P> 0.05). Group B and C increased greater compared with group A (P <0.01), Group C decreased significantly at 12h (P<0.01) and at 6h,24h,48h and 72h (P<0.05) than group B. Water content of brain tissue began to increase at 6h after resuscitation, reaching the peak at 24h, however begin to decline at 48 hours.㎝orphologic changes of brain structure with HE stain:clear structures, uniform distribution, and arranged appropriately of brain tissue was observed in group A. Group B and C demonstrated messy arranged, edema, loose and vacuolization structure of neural cell, with a lesson degree in Group C. Both group B and C showed a deeply stained nuclei with cytoplasm condensed.Conclusion Brain tissue began to showed serious edema, oxidative stress damage and inflammation reactions at 6h after SCA caused by suffocation. The damage was heaviest at 24h, declined at 48h,and turned to normal at 72h. (iNOS) inhibitor can suppress iNOS and NO expression in rat brain, decrease the concentration of serum CKT3B, reduce cerebral edema pathological damage. (iNOS) inhibitor was therefore considered to exert the protective effect on brain tissue. |
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