Cardiogenic shock is the leading cause of death among patients hospitalized with acute myocardial infarction （MI）. Understanding the mechanisms for acute pump failure is therefore important. The aim of this study is...Cardiogenic shock is the leading cause of death among patients hospitalized with acute myocardial infarction （MI）. Understanding the mechanisms for acute pump failure is therefore important. The aim of this study is to examine in an acute MI dog model whether mitochondrial bio-energetic function within non-ischemic wall regions are associated with pump failure. Anterior MI was produced in dogs via ligation of left anterior descending （LAD） coronary artery, that resulted in an infract size of about 30% of the left ventricular wall. Measurements ofhemodynamic status, mitochondrial function, free radical production and mitochondrial uncoupling protein 3 （UCP3） expression were determined over 24 h period. Hemodynamic measurements revealed a 〉 50% reduction in cardiac output at 24 h post infarction when compared to baseline. Biopsy samples were obtained from the posterior non-ischemic wall during acute infarction. ADP/O ratios for isolated mitochondria from non-ischemic myocardium at 6 h and 24 h were decreased when compared to the ADP/O ratios within the same samples with and without palmitic acid （PA）. GTP inhibition of （PA）-stimulated state 4 respiration in isolated mitochondria from the non-ischemic wall increased by 7% and 33% at 6 h and 24 h post-infarction respectively when compared to sham and pre-infarction samples. This would suggest that the mitochondria are uncoupled and this is supported by an associated increase in UCP3 expression observed on western blots from these same biopsy samples. Blood samples from the coronary sinus measured by electron paramagnetic resonance （EPR） methods showed an increase in reactive oxygen species （ROS） over baseline at 6 h and 24 h post-infarction. In conclusion, mitochondrial bio-energetic ADP/O ratios as a result of acute infarction are abnormal within the non-ischemic wall. Mitochondria appear to be energetically uncoupled and this is associated with declining pump function. Free radical production may be associated with the induction of uncoupling proteins in the mitochondria.展开更多
Subjective: To observe the effect of electroacupuncture (EA) of acupoints of the Heart Meridian and Lung Meridian on ischemic cardiac systolic ability for analyzing the relative specific relationship between the Heart...Subjective: To observe the effect of electroacupuncture (EA) of acupoints of the Heart Meridian and Lung Meridian on ischemic cardiac systolic ability for analyzing the relative specific relationship between the Heart Meridian and the heart. Methods: Acute myocardial ischemia (AMI) was produced by intravenous infusion of pituitrin (40 u + 5% glucose injection 500 ml, 60 drips/min) in the rabbit. Left intraventricular pressure (LVP), maximal rising velocity of LVP (dp/dt max), isovolumetric pressure (IP) and end-diastolic pressure (EDP) of the left cardiac ventricle were used as the indexes. Three points of Heart Meridian [HM, from 'Shenmen' (HT 7) to 'Lingdao' (HT 4)] and the three points of Lung Meridian [LM, from 'Taiyuan' (LU 9) to 'Lieque' (LU 7)] were punctured with filiform needles and stimulated with hand-manipulation and electrically with ZY2-1 EA Therapeutic Apparatus. 30 rabbits anesthetized with urethane (1 g/kg) were randomly and evenly divided into control group, HM group and LM group. Result-s: The effects of EA of HM points were evidently superior to those of EA of LM points in promoting the recovery of both AMI-induced decrease of LVP and dp/dtmax, and AMI-induced increase of IP and EDP. Conclusion: Acupoints of Heart Meridian has a relatively specific connection with the heart in comparison with those of Lung Meridian; and the Heart Meridian is a functional whole.展开更多
文摘Cardiogenic shock is the leading cause of death among patients hospitalized with acute myocardial infarction （MI）. Understanding the mechanisms for acute pump failure is therefore important. The aim of this study is to examine in an acute MI dog model whether mitochondrial bio-energetic function within non-ischemic wall regions are associated with pump failure. Anterior MI was produced in dogs via ligation of left anterior descending （LAD） coronary artery, that resulted in an infract size of about 30% of the left ventricular wall. Measurements ofhemodynamic status, mitochondrial function, free radical production and mitochondrial uncoupling protein 3 （UCP3） expression were determined over 24 h period. Hemodynamic measurements revealed a 〉 50% reduction in cardiac output at 24 h post infarction when compared to baseline. Biopsy samples were obtained from the posterior non-ischemic wall during acute infarction. ADP/O ratios for isolated mitochondria from non-ischemic myocardium at 6 h and 24 h were decreased when compared to the ADP/O ratios within the same samples with and without palmitic acid （PA）. GTP inhibition of （PA）-stimulated state 4 respiration in isolated mitochondria from the non-ischemic wall increased by 7% and 33% at 6 h and 24 h post-infarction respectively when compared to sham and pre-infarction samples. This would suggest that the mitochondria are uncoupled and this is supported by an associated increase in UCP3 expression observed on western blots from these same biopsy samples. Blood samples from the coronary sinus measured by electron paramagnetic resonance （EPR） methods showed an increase in reactive oxygen species （ROS） over baseline at 6 h and 24 h post-infarction. In conclusion, mitochondrial bio-energetic ADP/O ratios as a result of acute infarction are abnormal within the non-ischemic wall. Mitochondria appear to be energetically uncoupled and this is associated with declining pump function. Free radical production may be associated with the induction of uncoupling proteins in the mitochondria.
基金grants of State Scientific-technological Scale Project
文摘Subjective: To observe the effect of electroacupuncture (EA) of acupoints of the Heart Meridian and Lung Meridian on ischemic cardiac systolic ability for analyzing the relative specific relationship between the Heart Meridian and the heart. Methods: Acute myocardial ischemia (AMI) was produced by intravenous infusion of pituitrin (40 u + 5% glucose injection 500 ml, 60 drips/min) in the rabbit. Left intraventricular pressure (LVP), maximal rising velocity of LVP (dp/dt max), isovolumetric pressure (IP) and end-diastolic pressure (EDP) of the left cardiac ventricle were used as the indexes. Three points of Heart Meridian [HM, from 'Shenmen' (HT 7) to 'Lingdao' (HT 4)] and the three points of Lung Meridian [LM, from 'Taiyuan' (LU 9) to 'Lieque' (LU 7)] were punctured with filiform needles and stimulated with hand-manipulation and electrically with ZY2-1 EA Therapeutic Apparatus. 30 rabbits anesthetized with urethane (1 g/kg) were randomly and evenly divided into control group, HM group and LM group. Result-s: The effects of EA of HM points were evidently superior to those of EA of LM points in promoting the recovery of both AMI-induced decrease of LVP and dp/dtmax, and AMI-induced increase of IP and EDP. Conclusion: Acupoints of Heart Meridian has a relatively specific connection with the heart in comparison with those of Lung Meridian; and the Heart Meridian is a functional whole.
