| Objective: 1.Observed the change of electrocardiogram(ECG)in rats continuously after acute traumatic stress(ATS)and studied the changes of QT interval,QTc and ventricular arrhythmia(VA)in rats after ATS.The characteristics of the ventricular occurrence;2.The dynamic changes of KLF15 mRNA expression in myocardial tissue after ATS were observed,and the correlation between the KLF15 mRNA and the incidence of VA was analyzed to provide basis for the prevention and treatment of ATS.Methods:(1)10 SD rats(Sprague Dawley,SD rat)were used to establish an ATS model by amputation of the left hindlimb.The ECG of the amputated limbs was recorded consecutively for 60 min in the II lead,and the heart rate and QT interval were measured at one minute per observation period.The corrected QT interval(QTc)was calculated and the characteristics of ventricular arrhythmia were analyzed.(2)60 SD rats were divided into 6 groups: the observation group,the amputation 3 min group,the amputation 10 min group,the amputation 30 min group,the amputation 45 min group,the amputation 60 min group.The rats were sacrificed at corresponding time points,then ventricular tissue were taken timely.The mRNA expression of KLF15 in each group was detected by Semi-quantitative Polymerase Chain Reaction(SQ-PCR).Results:(1)After the amputation,the heart rate of the rats was faster,and the heart rate was the fastest at 3 minutes,which was 403.53±8.07 beats/min.Afterwards,the heart rate gradually decreased.The heart rate did not change obviously after 10 minutes of amputation,but it was still higher than the level before amputation;(2)The QT interval and QTc interval gradually decreased after amputation.The shortening time was the most obvious at 3 minutes after amputation,which was 0.27±0.09 s and 0.17±0.11 s.Since then,the QT interval and QTc interval gradually extended,and the length of the amputation was the most obvious.They were 0.53 ± 0.64 s and 0.41 ± 0.07 s,respectively,after which the QT interval and QTc interval gradually recovered to the level before amputation;(3)At 3 min after amputation,the mRNA expression of KLF15 in rat myocardial tissue was the highest,and the ratio of gray value with internal reference(?-actin)was 0.578±0.213.The mRNA expression of KLF15 in rat myocardial tissue at the amputation for 10 min was the lowest,and the ?-actin gray value was the lowest.The ratio was 0.297±0.372,after which the expression of KLF15 did not change significantly;(4)Within 3 minutes after amputation,the incidence of VA and VA scores were the highest,which were 27.01% and 3.2±1.317,respectively.The incidence of VA and VA scores were 21.84% and 2.2±0.789,respectively,3 to 10 minutes after amputation.There was no significant change in the incidence of VA and the VA score after 10 minutes of amputation.Conclusions:(1)Early ATS,rat ventricular myocardium was in an electrophysiological instability period,QT interval and QTc interval early shortened,and then gradually extended the dynamic process,and VA occurs in early ATS,when the rat QT,QTc interval shortened VA occurs more significantly;(2)In the ATS rat model,KLF15 mRNA expression also showed an early up-regulation and subsequent down-regulation of the dynamic changes. |
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