| Objective:To determine whether the animal model was successful by copying the rat model of acute myocardial ischemia,and using ECG,cardiovascular function,biochemical indicators and morphological changes,and then detecting myocardial ischemia at different times by Western blot and methylene blue Changes of H2S and CBS expression in rat central spinal cord,medulla and trigeminal spinal nucleus tissues,in order to investigate the temporal changes of central regulation of rats in the process of acute myocardial ischemia in rats,which is a clinical ischemic heart disease Prevention provides experimental basis.Methods:Animal experiment forty-eight male SD rats were randomly divided into 4groups（n=8）:（1）sham operation group;（2）ischemia 2h group（R2h）;（3）ischemia 3h group（R3h）;（4）ischemia 4h（R4h）.There were 24 in the sham operation group（8 at each time point corresponding to the ischemia group）and 8 in each group in the ischemia group.The left anterior descending anterior branch of the left coronary artery was ligated in the ischemic group,and the sham operation group was only threaded and not ligated.The electrocardiogram（ECG）of each group of rats was recorded through leadⅡ,and the changes of ST segment height,PR interval,QT interval,and Tp-Te interval were detected respectively;the right common carotid artery was catheterizedand the average arterial pressure was recorded（MAP）,heart rate（HR）,left ventricular developed pressure（LVDP）,left ventricular pressure maximum rise/fall rate（±dp/dtmax）and other hemodynamic indicators;ELISA method was used to detect the serum creatine in each group of rats Kinase（CK）and lactate dehydrogenase（LDH）activities;TTC staining was used to observe the changes of myocardial infarction area in each group of rats;Western blot was used to detect the central medullary nucleus oblongata,trigeminal spinal nucleus,and spinal cord C2 tissue H2S generating enzyme cystathionineβsynthase（CBS）expression;methylene blue spectrophotometry was used to detect hydrogen sulfide（H2S）in the nucleus medulla oblongata,trigeminal spinal nucleus,and C2 segment of spinal cord in each group of rats)Content.Results:（1）Changes in electrocardiogram of rats in each groupECG results showed that the HR in the R2h,R3h,and R4h groups were lower than the sham operation group at the corresponding time point（P<0.05）,the HR in the R4h group was lower than the R2h and R3h groups（P<0.05）,and the HR in other groups was not statistically significant Difference（P>0.05）;PR and（Tp-Te）/QT ratios in the R2h,R3h,and R4h groups were higher than those in the sham operation group at the corresponding time point（P<0.05）,PR and Tp-Te/QT ratios in the R4h group were all Higher than R2h and R3h groups（P<0.05）,PR and Tp-Te/QT ratios of other groups were not statistically different（P>0.05）;ST heights of R2h,R3h and R4h groups were higher than sham operations at corresponding time points In group（P<0.05）,the height of ST in R3h and R4h groups was higher than that in group R2h（P<0.05）,and there was no statistical difference in ST height in other groups（P>0.05）.（2）Changes in hemodynamics of rats in each groupCardiac function results showed that the MAP in the R2h,R3h,and R4h groups was lower than that in the sham-operated group at the corresponding time point（P<0.05）,the MAP in the R4h group was lower than the R2h group（P<0.05）,and there was no statistically significant difference in MAP among other groups（P>0.05）;R2h,R3h,R4h group（+dp/dtmax）/LVDP and-dp/dtmax are lower than the sham operation group at the corresponding time point（P<0.05）,and prolong with ischemic time（+dp/dtmax）/LVDP and-dp/dtmax decreased（P<0.05）;LVDP*HR in R2h,R3h and R4h groups were lower than the sham operation group at the corresponding time point（P<0.05）,LVDP*HR in other groups had no statistics Difference（P>0.05）.（3）CK and LDH activities in serum of rats in each groupThe results of biochemical indicators showed that the CK in the R2h,R3h,and R4h groups was higher than the sham operation group at the corresponding time point（P<0.05）,and the CK increased with the prolongation of ischemia（P<0.05）;LDH in the R2h,R3h,and R4h groups Both were higher than the sham operation group at the corresponding time point（P<0.05）.The LDH in the R4h group was higher than that in the R2h group（P<0.05）.There was no statistically significant difference in the LDH among the other groups（P>0.05）.（4）Changes in TTC staining of rat heart in each groupTTC staining results showed that compared with the sham operation group,the infarct area in the R2h,R3h,and R4h groups all increased（P<0.05）,and the myocardial infarct area increased significantly with the prolongation of ischemia time（P<0.05）.（5）The content of H2S in the trigeminal spinal nucleus,medulla oblongata nucleus and C2 segment of spinal cord in each group of ratsThe results of methylene blue spectrophotometry showed that the H2S content in the trigeminal spinal nucleus,medullary solitary nucleus nucleus,and spinal cord C2 tissues of the R2h,R3h,and R4h groups was lower than that of the sham operation group at the corresponding time point（P<0.05）The H2S content in the R3h and R4h groups was lower than that in the R2h group（P<0.05）,and there was no statistical difference in the H2S content in the other groups（P>0.05）.（6）CBS expression in the trigeminal spinal nucleus,medullary solitary nucleus,and C2segment of spinal cord in each group of ratsWestern blot results showed that the expression of CBS protein in the trigeminal spinal nucleus,medullary solitary nucleus,and spinal cord C2 tissues of the R2h,R3h,and R4h groups was lower than that of the sham operation group at the corresponding time point（P<0.05）,except R2h There was no statistically significant difference in the expression of CBS in the C2 segment of spinal cord in the R3h group（P>0.05）,and the other groups had statistical significance（P<0.05）Conclusion:During acute myocardial ischemia,the central H2S content and CBS expression of rats decreased with the prolongation of ischemic time,suggesting that endogenous H2S may participate in the central regulation of acute myocardial ischemia. |
PDF Full Text Request