The Expression Of Cardiac Connexin43 In Myocardial Infarction Patiens

Background and ObjectivesAcute myocardial infarction has been closely watching one of the serious clinical disease,its rapid progress, serious consequences, its incidence increased year by year, the mortality despite lower than before but still higher, to the health of the people brought great harm, it also increased the burden on society. Easily occur in patients with myocardial infarction or malignant ventricular arrhythmia arrhythmia or sudden death, now widely recognized that the mechanism of its addition to cell excitability and cardiac abnormalities, the electrical coupling and conduction abnormalities are major obstacles. Cardiac gap junction (gap junction, GJ) channels is the electrical coupling between myocardial cells and an important structure of chemical information exchange basis, and connexin 43 (conHexin43, Cx43) gap junction channels that form the heart, especially ventricular gap junction channels The main junction protein (connexin, Cx), the quantity, distribution and so if the change (Cx43 remodeling) is bound to lead to barriers to electrical coupling between myocardial cells and conduction abnormalities. Thus, connexin 43 after myocardial infarction remodeling and malignant ventricular arrhythmia is the molecular anatomy arrhythmia. Such as myocardial infarction in the early to take positive measures to intervene in the reconstruction of connexin 43, may control the occurrence of arrhythmia and even sudden death play a more active role.Ventricular connexin 43 is the major gap junction intercellular junction protein, in the electron microscope, connexin 43 was mainly in the intercalated disc cell clusters located in the junction end to end, every 6 months the connection between adjacent cell protein 43 constitute the transmembrane connection corpuscles, dozens of bodies lined up in the cell membrane constitutes a small gap junction. Special connection to access the area is rich, so these channels called gap junctions channels. Gap junction channel is hydrophilic, low selectivity and low resistance and so on, is the normal communication between cardiac cells and an important structure of chemical information exchange basis, the main role in the formation of intercellular electrical impulse conduction speed. Ensure that the overall electrical activity heart synchrony and coordination.The connection from the adjacent cell membrane protein hexamers riveted into the cell of low resistance gap junction channels shall myocardial cells, a cell conductance and conduction velocity of the main deciding factor. Although changes in ion channel function is an important factor in the arrhythmia, but not the coupling can play a major role in normal cells and sometimes, such as myocardial infarction, hypertrophic obstructive cardiomyo-pathy, cardiac amyloidosis, cardiac structure, such as imbalance, the impulse conduction disturbances, due to reentrant arrhythmias. Therefore, gap junction distribution in clarifying the mechanism of myocardial infarction changes of arrhythmias is important. In the mammalian heart, although the expression may have different connections, but mainly connexin 43. Therefore, the number of connexin 43 and distribution basically reflects the number and distribution.This study was designed to immunohistochemical staining to compare the myocardial infarction of connexin 43 (connexin 43, Cx43)distribution character-ristics of connexin 43 in coronary heart disease and changes of myocardial infar-ction diagnosis.MethodsExperiment from the Qingdao Municipal Hospital from 2007 to 2009 between autopsy work, save the heart of the samples selected 30 cases, samples are in line with the WHO diagnostic coronary heart disease death standard, coronary artery stenosis with lumen area divided into four narrow analysis. GradeⅠdisease:lumen area narrowed 1%-25%;Ⅱgrade lesions:luminal area narrowing 26%-50%;Ⅲgrade lesions:luminal area narrowing 51% 75%;Ⅳcolitis:narrowing the lumen area 76%-100%. Coronary heart disease in which 15 cases of myocardial infarction set to the experimental group,11 males and 4 females, according to drawn a different location will be set to B infarct group, infarct edge set C, non-infarct zone set D group. Another option 15 cases of violent deaths age-matched the experimental group, and non-sudden coronary death cases, is set as the control group A group, men 9 cases, female 6 cases. In the experimental group with myocardial infarction in coronary heart disease, take onemyocardium from each case on the site of myocardial infarction left ventric-ular area (infarctus zone), the non-infarcted myocardium (noninfarctuszone) and the edge of the infarct area (border zone). Because Cx43 uniformly distributed in the ventricular muscle layers, so in all cases in the control group taking a left ventricular myocardium to analyze the control.. Cleaned with normal saline to myocardial attachments, into 10% formaldehyde solution, fixed 24 h, removed 10 min after the rinse water after routine dehydration, clearing, paraffin, embedded. Paraffin sections, slice thickness of 4μm, each depicting 15 specim-ens,by immunohistochemistry SABC method, immunohistochemistry:sections of conventional dewaxing water→3% H2O2 to inactivate endogenous enzyme→Hot fix antigen enzyme digestion revealed normal rabbit serum antigen closed→dropping Cx43 antibody biotinylated goat serum→SABC→DAB color, in the above steps were all washed with PBS 5 min,Then dehydrated, transparent, neutral gum Fengpian, light microscopy; dyeing process of the other alternatives with PBS buffer as a blank control resistance. Random number for each section, under evaluation in the blind. Immunohistochemical staining positive cells count, high power field (×400) randomly selected the next five horizons, followed by counting the calculation for each field of vision and the total number of Cx43-positive GJ. Measurement of vision in the positive area, according to an area of cells positive for protein expression in a semi-quan titative experimental data with mean±standard deviation (x±s) that the application of Beihang MAIS pathological image analysis of connexin Cx43 expression, statistical test data.Results1. Gross observationThe experimental group with coronary heart disease myocardial infarction cardiac sudden death in 11 cases of male and 4 female (average age 45 years). General increase in cardiac left ventricular wall thickening. Among them, two cases of cardiac rupture, rupture area in the anterior wall in 1 case, ventricular septal rupture in 1 case,1 case of bleeding associated with myocardial rupture zone. Eight cases of cardiac hypertrophy expansion, six cases of heart left ventricular anterior, lateral, septal, left ventricular posterior wall myocardial infarction, and there is the coexistence of old lesions; while the remaining 9 patients had focal lesions of myocardial infarction and with myocardial bleeding. Each case is accompanied by one or more than one coronary artery stenosis≥75%, coronary artery hemorrhage, rupture and other symptoms. In the age-matched control group,9 cases were male and 6 female patients (average age 43 years), the heart showed no evidence of cardiac enlargement in general, no coronary artery stenosis and ischemia is found.The time from death to autopsy, the experimental group 6～50 h (average 24 h), control group,8～32 h (average 22 h).2. Heart HE staining:Microscope, experimental group, coronary atherosclerosis, and some patients had cholesterol crystals and calcium deposits; 8 cases of myocardial interstitial expansion, blood stasis; six cases of cardiac papillary muscle fiber breakage; each were found in cases of varying degrees of myocardial degeneration, necrosis, myocardial see the inside of old fibrous scar tissue, of which there are varying degrees of myocardial fiber fracture, myocardial intercalated disc structure disappeared. In the control group, we see that normal cardiac structure, there is a small number of cases found in the outer membrane of myocardial regional myocardial hemorrhage, cardiomyocyte intercalated disc structure between the visible.3. Cx43 immunohistochemical staining:The normal cardiac muscle (control group) arranges obviously has the high regular phosphorylation connection protein 43 to concentrate in the cardiac muscle intercalary plate place; Assumes the bunch of shape distribution in the cardiac muscle textile fiber major axis vertical cell neat connected spot obvious slit connection, but only has the minority slit connection to be located with the cardiac muscle textile fiber major axis parallel cell side side connected spot; Connects protein 43 in cardiac muscle each to have the dense distribution, had not discovered the connection protein 43 density remarkable markups or reduces region.At the coronal atherosclerosis heart disease cardiac arrest sudden death case of illness (experimental group), the different cardiac muscle spot slit connection protein Cx43 masculine gender expression difference quite is big. Compared with the normal myocardium, infarct lesion and its adjacent areas the distribution of Cx43 apparent disorder, part of the central area of infarction Cx43 has completely disappeared, while some central area of infarction there is a small part of the Cx43 proteins re-distribution, are scattered throughout the cytoplasm; In the marginal zone and the necrotic area adjacent to at most Cx43 has disappeared, only a very small number of Cx43 is found in myocardial cells at side to side phase. Can also be found in the vicinity of the edge with a number of island, peninsula-shaped still viable myocardium,Cx43 is found in myocardial cells of some side-side-phase office. Can also be found in the vicinity of the edge with a number of island, peninsula-shaped still viable myocardium, a number of a small amount of the distribution of Cx43-positive proteins in these regions are still viable myocardium. In addition, non-infarcted myocardium in the morphology of its kind at a normal (possibly survive), but the cells of the intercalated disk between the collapse of Cx43-positive severe damage, especially cells in terminal-terminal phase of the Cx43 at all but disappeared, re-distributed in the cells, side-side-phase office.ConclusionExpression of gap junction Cx43 is characterized markedly by inhom-ogeneity in distribution and density in heart of SCD with myo cardial infarction, which accounts for the fatal arrhythmia.Also the experiment shows that Cx43 dephosphorylation is valuable in diagnosis of this disease.