| Heart failure is the final stage and major cause of death in most cardiovascular diseases.Recent clinical studies have found that cardiovascular diseases,especially patients with heart failure,are often accompanied by significant cognitive impairment and/or anxiety and depression.The "Heart controlling mental activities" theory is one of the important classical theories of Chinese medicine.Although the connotation and extension of the concept of"Heart" of Chinese medicine is greater than the heart of modern medicine,the function of the heart is the core content of "Heart" of Chinese medicine."Heart controlling mental activities"indicates the close relationship between the physiological activity of the heart and the person's mental activity.More and more evidence has been found that the function of the heart can affect the brain's thinking function,but its mechanism is not yet clear.The changes in the brain ultrastructure and neurotransmitters are closely related to the cognitive function.This study focuses on cognitive dysfunction after heart failure that threatens human health.The model of rat heart failure after myocardial infarction was used as the study object.After heart failure,the ultrastructure of rat parietal lobe and changes in neurotransmitters were explored.The pathological mechanism of cognitive impairment hopes to provide a basis for the theory of"Heart controlling mental activities" in Chinese medicine to some extent.Objectives:1 A rat model of myocardial infarction induced by ligation of the left anterior descending coronary artery was established.The correlation between pathological Q waves and echocardiographic parameters of the model rats was analyzed to establish a method of early evaluation and screening of the rat model of heart failure after myocardial infarction.2 The Morris water maze test was used to detect the cognitive function of rats with heart failure,and the changes in behaviors such as learning and memory ability after heart failure in rats were explored.3 To study the changes of the ultrastructural and various neurotransmitters of the parietal brain regions in rats with heart failure after myocardial infarction.Methods:1 SD rats were randomly divided into sham-operated group and model group.Rats with myocardial infarction were established by ligation of the left anterior descending coronary artery to cause coronary artery occlusion and myocardial ischemia.The rat model of electrocardiography was established.Correlation analysis of sexual Q wave and echocardiographic parameters,establishment of early evaluation and screening methods of heart failure rat model.2 Morris water maze test was used to detect spatial learning and memory in rats with heart failure after myocardial infarction.Set up navigation experiments and space exploration experiments.3 The changes of neurons,various organelles,synapse structure and blood-brain barrier in the parietal cortex of rats with heart failure after myocardial infarction were observed by electron microscopy,and the number of synapses was quantitatively analyzed.4 The content of acetylcholine,seven kinds of amino acid neurotransmitters,and six monoamine neurotransmitters in the parietal cortex of rats with congestive heart failure were detected by mass spectrometry.Results:1 Compared with sham-operated rats,rats with heart failure after myocardial infarction were significantly impaired in cardiac function,left ventricular ejection fraction(LVEF),and shortening of the short axis of the left ventricle in the echocardiography model group rats 60 days after surgery.LVFS)were significantly decreased(P<0.001),left ventricular end diastolic diameter(LVDd),left ventricular end-systolic diameter(LVDs),left ventricular end-diastolic volume(LVEDV),left ventricular end-systolic volume(LVESV),left ventricular end-diastolic anterior wall thickness(LVAWTd)and left ventricular end-systolic anterior wall thickness(LVAWTs)were significantly increased,and left ventricular posterior wall systolic thickness(LVPWTs)was significantly decreased(P<0.001).Left ventricular posterior wall There was no significant difference in end-diastolic thickness(LVPWTd)(P>0.05).ECG examination showed that there were still ST-segment elevations or pathological Q waves in the model rats.The correlation between the number of electrocardiogram pathological Q-waveguides and the echocardiographic EF and FS values showed that the number of pathological Q waves and EF and FS were negative in the ECG of the model group on the 2nd and 60th days after operation.Correlation,the specificity of early screening for heart failure rats by this method was 100%(20/20),sensitivity was 90%(18/20),and accuracy was 95%(38/40),2 The Morris water maze test was performed on model rats and sham-operated rats.There was no significant difference in the escape latency,total swimming distance and cognition rate between the two groups of rats in the positioning navigation test(P>0.05).In the spatial probe trial,the number of times the rats traversed the original hidden platform was obviously decreased with the sham group(P<0.05).3 The results of electron microscopy showed that there were changes in the structure of neurons,endothelial cells,and astrocytes in the parietal cortex of model rats,and synapses decreased.In this results for specific performance:a large number of neurons repressed,the less concentration of cytoplasm and most of the cells striped;mitochondria abnormal swelling and deformation,vacuolated,mitochondrial crista breakage,rough endoplasmic reticulum dilated and degranulation,the Golgi expansion with different degrees;ribosome depolymerized;the nuclear membrane deeply stained,invaginated,concentrated and deformed;the nuclear gap widened;a large area of edema around the capillaries visible,the structure of the endothelial cells and the basement membrane destroyed,the boundaries blurred,swellings of varying degrees appeared,and the mitochondria around the blood vessels also showed swelling and structural destruction.Astrocytic lesions are also more serious,mainly manifested by large edema of cell processes,large blank areas,and destruction of mitochondria bilayer membrane structure.In addition,compared with sham operation group,the number of synapses in parietal brain area of model group was significantly reduced(P<0.05).4 Through mass spectrometric detection of 14 neurotransmitters,including acetylcholine,amino acid neurotransmitters,and monoamine neurotransmitters,it was found that the rats in the model group had aspartic acid(Asp)in the parietal lobe region compared to the rats in the sham group.Gamma-aminobutyric acid(GABA)and phenylalanine(PHE)and other neurotransmitters all showed a significant decrease(P>0.05);acetylcholine and monoamine neurotransmitters in both groups There was no significant change between the two groups(P>0.05).Conclusion:1 Pathological Q waves are distributed in V3-V6 leads,I leads and AVL leads,and lead V1 or V2,and pathological Q waves should be greater than 7 leads as an early screening method for rats in the model group The higher level of sexuality can provide important theoretical basis and method guidance for the success or failure of rat model of heart failure after myocardial infarction,judgment of heart failure degree,homogeneity of experimental group,and early intervention of pharmacological experiments.2 There was obvious spatial memory impairment in Chronic heart failure rats,which is consistent with the situation of patients with heart failure.Morris water maze positioning navigation experiment is not sensitive to the evaluation of cognitive dysfunction of the model.3 The changes of ultrastructure of parietal brain regions in rats with cognitive impairment after heart failure were mainly showed the loss of neurons and pyknosis,the decrease of synapses,the swelling and deformation of mitochondria and Golgi apparatus,and the edema of endoplasmic reticulum,degranulation,as well as the destruction of the blood-brain barrier structure.4 The cognitive impairments in rats with heart failure after myocardial infarction are related to the decrease of amino acid neurotransmitters in the parietal regions of the rat brain.The main manifestations are aspartate(ASP),aminobutyric acid(GABA)and phenylalanine(PHE)levels decreases in the parietal lobe region of rats.5 Chinese medicine believes that "the heart is the main blood,heart controlling mental activities," and "the heart is hidden." When the function of the "heart main blood vein"occurs,the function of the " heart controlling mental activities " is abnormal,and its scientific connotation and brain cognitive function decline,brain Structural destruction and abnormalities of neurotransmitters are closely related. |
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