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Objective To explore mechanism ( s) is dynamic expression and internal relations of c-kit gene and miR-21 in rat ventricular remodeling .Methods SD rats( n=140) were randomly divided into normal control group ( n=15 ) and heart failure model group ( n=125 ) .Heart failure model:4 mg/kg intraperitoneal injection of adria-mycin.To detect the cardiac function of rats in eight weeks , proving the heart failure .Then harvest the rat heart , frozen section , using immunohistochemistry and immunofluorescence color to detect the expression changes of miR-21 and c-kit in myocardial tissue .Results The emergence of the pathological changes of cardiac muscle cells after myocardial infarction in the heart failure groups and the control group didn't appear the myocardial infarction and heart failure .Immunohistochemistry and immunofluorescence show that miR-21 positive cells in normal and heart failure myocardium mainly express in vascular endothelium ,a few myocardial cells and stem cells , and endocardial expressing quantity fell more than epicardial;c-kit positive cells tend to cluster together , mainly gather in the epi-cardial and its nearby , and the expressing quantity decrease significantly after heart failure .A small number of cells exsit miR-21 and c-kit common expression in both groups ( P<0.05 ) .Conclusions The decreased expression of c-kit and miR-21 is highly related to rats heart failure and left ventricular remodeling .
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BACKGROUND:Col agen type II and proteoglycan loss are two most obvious manifestations of cartilage damage in the onset of osteoarthritis. Changes in col agen type II and proteoglycan as the main components of cartilage matrix directly lead to cartilage degeneration and subsequently result in osteoarthritis. How to reverse or prevent the development of this process becomes the focus of medical research. OBJECTIVE:To observe the effect of warming yang and benefiting marrow recipe on the expression of col agen type II and proteoglycan in the articular cartilage of knee osteoarthritis rabbits as wel as to further explore the mechanism underlying chondrocyte protection. METHODS:Ninety-six New Zealand rabbits, aged 9 months old, male and female, were selected to prepare osteoarthritis models in extension position using cast immobilization method, and were randomly divided into four groups:blank group (untreated), model group (simple modeling), Chinese medicine group (intragastric administration of extracts of warming yang and benefiting marrow recipe, 24 mL/kg/d) and western medicine group (intragastric administration of glucosamine hydrochloride, 24 mL/kg/d). Intragastric administration was done once a day for 6 weeks. RT-PCR technology was used to observe the effect of warming yang and benefiting marrow recipe on the expression of col agen type II and proteoglycans in the articular cartilage, and pathological examination was also done. RESULTS AND CONCLUSION:The cartilage surface was smooth in the blank group and Chinese medicine group, with uniform toluidine blue staining, but in the model group and western medicine group, the cartilage surface was rough and the toluidine blue staining was extremely uneven with obvious loss of surface and middle layer dying. The expressions of cartilage proteoglycan and col agen type II in the model group were significantly lower than those in the blank group (P<0.01) as wel as in the Chinese medicine group and western medicine group (P<0.05). In addition, the expressions of cartilage proteoglycan and col agen type II in the Chinese medicine group were higher than those in the western medicine group (P<0.05). These findings indicate that the recipe of warming yang and benefiting marrow can enhance the expressions of col agen type II and proteoglycan, which can maintain the normal col agen phenotype and protect the articular cartilage.
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Objective To develop a method of studying fiber projecting in the spinal cord duiring chicken embryo development.Methods At embryonic incubation 3 day (E3), pCAGGS-green fluorescent protein (GFP) plasmid was injected into the spinal cord using in vivo electroporation.Three days after transfection (E6), GFP-positive embryos were collected under a stereo fluorescence microscope .Subsequently , the spinal cord was separated from the embryos and cut from the roof plate as an open book .After fixed with 4%paraformaldehyde ( PFA) for one hour , the opened spinal cords were used for immunohistochemistry with N-cadherin antibody and with DAPI for nuclei .Finally, the nerve fiber projecting was photographed and analyzed under a fluorescence microscope . Results Based on the opened spinal cord and immunostaining in the cryosection , we observed that the nerve fibers projected across the midline of the floor plate and reached to the sulcus terminalis along the white matter of the contra side .The immunoreaction against N-cadherin indicated that overexpression of GFP has no significant effect on chicken embryonic development .Conclusion A new method to study fiber projecting in the developing chicken spinal cord is established successfully in this study .
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Objective To investigate the effect of ischemia and ischemia/reperfusion(I/R)in rat heart on matrix metalloproteinase-1(MMP-1).Methods The I/R animal models were established by shutting down and reopening the anterior interventricular branch with a silver clamp,then the distribution and amount of MMP-1 of the normal and I/R rat hearts were observed by immunohistochemical staining and Western blotting and analyzed by computer image analysis.Results 1.Immunohistochemical staining showed MMP-1 existed mainly in the cardiac matrix.There were strong positive reactions in fibrocytes,smooth muscle cells of the blood vessel and endotheliaI cells of capillaries.MMP-1 didn't show distinct changes 30 minutes after ischemia,while its concentration increased dramatically 60 minutes after ischemia.The positive reaction of MMP-1 increased 30 minutes after I/R,and 60 minutes after I/R there was large fusion areas in MMP-1 existing reglons.2.Quantitative analysis showed no dramatic changes of MMP-1 after ischemia for 30 minutes(P＞0.05),while dramatic changes were seen 60 minutes after ischemia(P＜0.05).MMP-1 changed dramatically 30 minutes and 60 minutes after I/R.3.Western blotting showed that there were no distinct naked-eye-observable changes.The bands of MMP-1 became widened 30 minutes after I/R,and became obviously widened 60 minutes after I/R.Conclusion 1.MMP-1 is secreted by fibrocytes,smooth muscle cells and endothelial cells of cardiac tissue under physiological conditions,and cardiomyocytes has the potential to secrete MMP-1 under ischemia or I/R.2.The longer time the heart ischemia lasts,the greater MMP-1 concentration will increase.Reperfusion can increase MMP-1 concentration to an even higher level,which may be the main cause of the collagen destruction after heart I/R.
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<p><b>OBJECTIVE</b>To investigate the effects of Egb761, an extract of ginkgo biloba , and dipyridamole on inducible NO synthase (iNOS) in rabbits after myocardial ischemia-reperfusion injury.</p><p><b>METHODS</b>After being established into ischemia-reperfusion injury model, 35 rabbits were divided randomly into 5 groups: Group A (the sham group), Group B (the model group), Group C (treated with dipyridamole 0.8 mg/kg), Group D (treated with Egb761, 40 mg/kg), and Group E (treated with Egb761 40 mg/kg combined with dipyridamole 0.8 mg/kg), all the medications were administered by intravenous injection 30 min after reperfusion. After administration, myocardial iNOS mRNA expression was detected by RT-PCR and western blot.</p><p><b>RESULTS</b>Myocardial iNOS mRNA transcriptive expression in the 5 groups were A 0, B 157.11 +/- 17.73, C 202.6 +/- 21.84, D 356.13 +/- 24.18 and E 562.34 +/- 35.19 respectively, showing significant difference between the treated groups and group B (P <0.01). The translative expression of myocardial iNOS in the 5 groups were A 34.24 +/- 15.78, B 75.70 +/- 13.71, C 116.89 +/- 22.57, D 143.75 +/- 16.05 and E 195.09 +/- 22.25 respectively, showing significant difference between the treated groups and group B as well (P < 0.05, P < 0.01).</p><p><b>CONCLUSION</b>Both Egb761 and dipyridamole could increase myocardial iNOS expression in transcriptive and translative levels in rabbits after myocardial ischemia-reperfusion injury, and the combined treatment of them shows a more significant effect.</p>
Subject(s)
Animals , Female , Male , Rabbits , Dipyridamole , Therapeutic Uses , Drugs, Chinese Herbal , Therapeutic Uses , Ginkgo biloba , Myocardial Reperfusion Injury , Drug Therapy , Genetics , Myocardium , Nitric Oxide Synthase Type II , Genetics , Phytotherapy , RNA, Messenger , Genetics , Random Allocation , Transcription, GeneticABSTRACT
BACKGROUND: Macula adherens protein is found closely associated with congenital cardiac malformation and myocardial differentiation. OBJECTIVE: To investigate the expression characteristics of α-macula adherens protein in rat heart, as well as the property of age-dependant expression during myocardial growth. DESIGN: Randomized controlled, observational comparative study. SETTING: Department of Cell Biology of Xinxiang Medical College; Department of Bioengineering and Agricultural Economics of Puyang Vocational Technical School. MATERIALS: This study was conducted at the Morphological Laboratory of Xinxiang Medical College between January and June 2003. Totally 28 Wistar rats of clean grade were divided into infant group, youth group,middle-age group, and old-age group with 7 rats in each group. METHODS: All rats were anaesthetized and then cardiac tissues were cut into consecutive coronal slices of 5 μm thick. The expression of α-macula adherens protein in rat myocardium of infant, youth, middle-age and oldage groups was detected using IHC method. The positive cells displayed brownish yellow granules on the surface, cytoplasm and intercalated disc. Routine HE staining was performed on all specimens for structural comparison. MAIN OUTCOME MEASURES: The expression of α-macula adherens protein in rat myocardium of different groups. RESULTS: All the 28 rats entered the final results analysis. ① α-macula adherens protein was found to be expressed in myocardium in atrium, ventricle, papilla muscles and interventricular septum. ② In infant rats, the expression of α-macula adherens protein was mainly observed in intercalated disc at the end of myocardium, with less expression on cell surface and in cytoplasm; in contrast, α-macula adherens protein in young, middleaged and old rats was found to be typically expressed in intercalated disc at the end of myocardium. CONCLUSION: The expression of α-macula adherens protein displays age-dependant manner during rat myocardial development; moreover, the expression of α-macula adherens protein is found to be consistent with the development of intercalated disc.
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BACKGROUND: Type Ⅰ and type Ⅲ collagen, the main components of cardiac stroma,have supporting,protective and restrictive effects on myocardial cells. They are essential for the heart to maintain its normal shape and function. OBJECTIVE:To explore the effects of types Ⅰ and Ⅲ collagen on cardiac function by observing their changes in atrium myocardium of children with ventricular septal defect (VSD). DESIGN: A case analysis. SETTTING: Department of Cytobiology, Xinxiang Medical College. PARTICIPANTS: Six children who had died from accidents were selected from the Pediatric Department of the First Affiliated Hospital,Xinxiang Medical College, between January and August 2003. Informed consent was obtained form their relatives. They were 4 males and 2 females,ranging from 1 to 15 years in age. Congenital heart diseases were excluded by naked-eye anatomical examination,and right atrium tissues were collected for the study. Meanwhile, 21 children with VSD, 12 males and 9 females aged 1-17 years,were recruited from the Department of Cardiac-thoracic Surgery of the same hospital. METHODS:A small amount of fresh myocardium was cut from the right atrium at the edge of incision. Peroxidase-labeled strepto-avidin immunohistochemical method was adopted to detect the expression of types Ⅰ and Ⅲ collagen protein in atrium myocardium, which was analyzed using image analysis to calculate the area composition ratio of type Ⅰ and type Ⅲ collagen in atrium myocardium(representing the relative area percentage of collagen protein) and area percentage (representingthe expression percentage of collagen protein). MAIN OUTCOME MEASURES:Expression of typeⅠand type Ⅲ collagen protein in atrium myocardium. RESULTS: Six normal controls and 21 patients with VSD entered the final statistical analysis. ① Type Ⅰcollagen of normal atrium was strip-like fibers with different diameters connected with each other,whereas type Ⅲ collagen was scattered in spots and pieces. ② The distribution of type Ⅰ and Ⅲ collagen of atrium in VSD patients was mostly similar to that of the normal controls; only part of them displayed extreme rearrangement, that is,type Ⅰcollagen presenting large-speckle increment,breakage or disappearance, while type Ⅲ collagen increased in stripes and bundles. ③ The area percentage and area composition ratio of type Ⅰ and type Ⅲ collagen:type Ⅰ collagen expressed more than type Ⅲ collagen in normal myocardium [area percentage: (48.82±12.35)％ vs (40.02±13.53)％, t=2.173, P ＜ 0.05;area composition: (15.87±6.03) μm2 vs (13.62 6.94) μm2, t=2.221, P ＜ 0.05].Likewise, type Ⅰ collagen expressed more highly than type Ⅲ collagen in VSD myocardium [area percentage: (55.37±10.42)％ vs (50.27±14.36) ％,t=2.173, P ＜ 0.05; area composition: (24.93±9.62) μm2 vs (19.22 12.03) μm2,t=2.221, P＜ 0.05]. The content of both type Ⅰ and type Ⅲ collagen in VSD children was obviously higher than that in normal children(t=2.153-2.234,P ＜ 0.05). CONCLUSION: In children with VSD, part of type Ⅰ and type Ⅲ collagen is found rearranged and increased in atrium, which may result from the interstitial compensation due to cardiac dysfunction.
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Objective To study the relation between vascular endothelial growth factor(VEGF) and the degree of coronary artery stenosis as well as the formation of collateral circulation in patients with acute myocardial infarction (AMI). Methods Seventy-six cases of AMI had undertaken selective coronary angiography on the third to seventh day after admission and also at six months afterwards in order to define the degree of coronary artery stenosis and the presence of collateral circulation. A blood sample of 5 mL was taken in each patient before the first coronary angiography to test for the level of VEGF by enzyme linked immunosorbend assay. Results The level of VEGF in patients with coronary artery stenosis less than 50%, 50%~75% and greater than 75% were (97.6?17.3) ng/L, (241.6?28.9) ng/L and (391.7?48.4) ng/L respectively (P
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Objective To observe the structural characteristic of Marshall ligament and coronary sinus of 40 dog hearts. Methods The Marshall ligament and coronary sinus of 40 dog hearts fixed with 10% formaldehyde were observed in gross anatomy. Results The Marshall ligament begins at the right external side edge of left atrium appendage, via the left inferior pulmonary vein to the inner surface of pericardium. The length and the width of Marshall ligament of dog hearts were (2.61?0.95) cm, (0.18?0.04) cm respectively. The angle between Marshall ligament and the coronary sinus was (116?11), and the shortest length between Marshall ligament and left atrium was (0.58?0.52) cm. The length and the width of coronary sinus was (2.84?0.85) cm, (0.28?0.07) cm respectively. There are lots of cardiac fibers of ring (47.5%), vertical (37.5%) and diagonal (15%) shape on the surface of coronary sinus. Conclusion A lot of muscle fibers attaching to the surface of Marshall ligament and coronary sinus in dog hearts are abnormal atrial channels. Dog is the favorable animal for research of focal atrial fibrillation.
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Objective To investigate the differences of connexin 43(Cx43)expression between adult and infant heart. Methods By using immunohistochemistry to observe the expression of Cx43. Results 1.The expression of Cx43 had a punclate distribution in cytoplasm and over the entire surface of the cardiocyte,and a few located at intercalated disk of atrial and ventricular myocardium in the infant heart.2.Cx43 positive granules distributed irregularly in cell side surface and cytoplasm as well as intercalated disk in adult atrium.Cx43 immunolabelling of adult ventricular myocardium was typically confined to the site of intercalated disk.3.The results of image analyzer showed that the amount of connexin43 expression was lower in the atrium than that of the ventricle in infant heart and atrium bigger than ventricle in adult heart.The expression of Cx43 was less in adult heart than that of infant heart.Conclusion The expression of Cx43 was mainly over the entire surface of the myocardium in infant heart.There were expression differences of Cx43 in human ventricular and atrial myocytes.The amount of Cx43 expression was higher in ventricle than that of atrium in infant heart and atrium bigger than ventricle in adult heart.It was less in adult heart than that of infant.It showed that the expression of Cx43 in human heart existed a developmental differences.
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Objective To research pacemaker cells outside conductive system of rat and mouse heart. Methods Paraffin and frozen serial sections (stained with HE, Masson, cholinesterase technique), and ultrastructural sections, from atrial tissue of 10 rats and 15 mice were observed by light and electron microscopy to find latent pacemaker-like cells. Results Some round or elliptical cells were scattered and irregularly detected in right and left atrial tissue of rat and mouse. Their nuclei were larger, plasma was clearer and cellular organelles were fewer than those of working myocyte. These cells were similar to pacemaker cells in sinoatrial node.Conclusion There are some pacemaker-like cells in right and left atrial tissue of rat and mouse. The finding can provide a morphological basis for ectopic beat of atrium.
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Objective To investigate the biocompatibility between the atelocollagen scaffold and 3D-cultured myocardial cells,and to find out the condition and an optimal biomaterial scaffold that can be applied to 3D-culture myocardial tissue. Methods The primary cultured myocardial cells were purified and then inoculated into the atelocollagen scaffold.The cells in the atelocollagen scaffold were observed by light microscope,scanning electron microscope(SEM) and transmission electron microscope(TEM) at different times(8d,16d,20d). Results On the first day,cardiac cells pulsating together with the atelocollagen scaffold could be detected under the microscope,which were pulsating complex.A plenty of cells in the atelocollagen mesh were observed under the light microscope,and the cells coalesced with the scaffold.The cells were compacted to the scaffold and coalesced with it at three stages under TEM.Those cells were sticked to the atelocollagen scaffold and expanded sufficiently under SEM.On the atelocollagen scaffold surface,these cells coalesced with lamellar.Conclusion The biocompatibility of the atelocollagen scaffold is better for cultured cardiac myocyte.It can be used as a natural material for 3D-cultured cells,and is suitable for 3D-cultured cardiac cells and cardiac tissues.
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Objective To investigate cell type and size of fetus atrioventricular node. Methods Using the technique of paraffin section, H-E staining, the cellular morphology and size of atrioventricular node in fetus hearts were observed under microscope, and quantitied by HIPAS-1000 computerized image analytical instrument. Results The cell types of atrioventricular node in fetue hearts were composed of light, dark and transitional cells. The morphology of light and dark cells were spindle-shaped or ellipsoid, but a few cells were polygonal. The shape of transitional cells was short column. The nuclei of light cells and transitional cell were larger than that of dark cells.Conclusion Pacemaker cell of atrioventricular node in fetus heart includes light and dark cells which could present different function types of pacemaker cell. [
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Objective To investigate age-related changes of type Ⅰ and Ⅲ collagen in rat heart. Methods Twenty-one male Wistar rats were divided randomly into infanct,young and old group.Types Ⅰ and Ⅲ collagen expresson of different age hearts were studied by SP immunohistochemical methods. Results 1.Type Ⅰ and Ⅲ collagen all constitute thick fiber and fibril.The fibrils encircled every cardiac muscle and formed collagen net each other.The thick fibers being plaque were located among cardiac muscle groups.The content of type Ⅰ collagen was more than that of type Ⅲ.2.There were distinct expression difference of type Ⅰ and Ⅲ collagen in different aging rat hearts.The collagens distributed densely and evenly in infancy rat heart,and loosely and uniformly in young rat heart,and the contents were increased distinctly with heterogeneous distribution in old rat heart.The cardiac collagen was growing from infanct to old rat,and rapid progress of cardiac collagen was seen in young rat. 3.The content of collagen in right ventricle was more than that of left ventricle of infanct heart.The collagen in all parts of the heart is not of difference both in yound and old rat. Conclusion The contents of type Ⅰ collagen is more than that of type Ⅲ collagen.The two types collagen are increasing with growing.;
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Objective To investigate the spatio-temporal expression of connexin 43(Cx43) in the cultured ventricular myocardial cells of neonatal rats. Methods The techniques of Immunocytochemistry(ICC) and immuno-electron microscopy were used to detect the Cx43 expression in the cultured rat ventricular myocardial cells on the(2nd),(4th),(8th),(10th),(12th),(16th),(20th,)(26th) and(30th) days. Results Cx43 expression was detected in the cultured ventricular myocardial cells on the 2(nd) day,and the Cx43 granules were located largely in the cellular cytoplasm and membrane.The punctiform granule of the cellular cytoplasm decreased and the expression of Cx43 was located mainly in cellular membrane junction on the 4(th) day.The expression of Cx43 increased in cellular membrane junction on the 10(th) day,and the morphology of Cx43 expression was chain-and strip-like.There were not obvious changes in the following days.The expression of Cx43 on the 30(th) day was derangement.Conclusion The spatio-temporal expression of Cx43 in the cultured ventricular myocardial cells of neonatal rats changed with the cultural time in terms of location and quantity.It was in accordance with the growth and development of the cultured ventricular myocardial cells.
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Objective To investigate expressional pattern of the Connexin 43 in atrial myocytes of ventricular septal defect children. Methods The expressional role of the Connexin 43 in atrial myocytes of ventricular septal defect children were observed and determinated by immunohistochemistry and digital image analysis technology. Results 1.The Connexin 43 granules of 1-3 year-old-group normal children were mainly distributed on cell side surface,which took on beening spot-,belt-or chain-shaped,but seldom at intercalated disks. The Connexin 43 of 7-16 year-old-group normal children were abundantly distributed on cell side surface and intercalated disks. 2.The Connexin 43 of 1-3 year-old-group ventricular septal defect children were not noly distributed on cell side surface but could be detected at intercalated disks and cytoplasm,a few granules were irregular in arrangement.The Connexin 43 of 7-16 year-old-group ventricular septal defect children were distributed on cell side surface and in cytoplasm but seldom existed at intercalated disks,and arranged in irregular order. 3.The experimental results showed insignificant difference in the expressional amount of the Connexin 43 in atrial myocytes between the ventricular septal defect children and normal children. Conclusion The Cx 43 distributional pattern in atrial myocytes of ventricular septal defect children was changed,but its expressional amount was indistinct,which suggested that ventricular septal defect affected only the Cx43 expressional pattern.
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Objective To research the spatiotemporal pattern of N-cadherin expression during development of rat cardiomyocytes and age-related changes of N-cadherin expression. Methods Using immunohistochemical method,myocardial N-cadherins distribution was investigated in fetal rat and postnatal development(1 postnatal day to old rat),and quantitied by HIPAS-1000 computerized image analytical instrument. Results The expression of N-cadherin was located in myocardium of atrial and ventricule and septum interventriculare and papillary muscles.The N-cadherin immunolabeling was found in myocyte membranes and within cytoplasm in fetal rat heart.From neonatal to infant rat,the pattern of N-cadherin immunolabeling changed progressively,from being dispersed over the entire cell surface as in the fetal to the transverse terminals of the myocytes,toward the distribution within the intercalated disk.From young to old rat heart,the typical N-cadherin was located in transversely orientated intercalated disk.The percentage of N-cadherin immune postive area in rat ventricular myocardium showed a progressively changement with age.Conclusion The present paper demonstrated that the N-cadherin expression exists progressively with ages and the changing pattern of N-cadherin is closely related with development of the intercalated disk in rat myocardium.The mechanical coupling provided by adherens junctions is essential for the stable cell-cell contact.
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Objective To study the expression of telomerase(TMA) in myocardial tissue of myocardial ischemia in rat. Methods Sixty Spraque-Dawley rats were randomly divided into A,B, C three groups,then each group was randomly divided into control group and testing group.Two myocardial ischemia groups were injected isoprenaline(8 mg/kg),and two control groups were injected distilled water(8 mg/kg) in abdominal cavity.For the last myocardial ischemia group the coronary artery was ligated.The histological and immunohistochemical method were used for observing cardiac structural changes,with HE staining,and changes of TMA in myocardial tissue after myocardial ischemia in rat.The TMA contents were measured by image analysis. ResultsCompared with the respective control group,the expression of TMA in the three myocardial ischemia groups increased obviously(P
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Objective To probe distribution and excreting cells of type I collagen in rat heart. Methods Expression of cardiac collagen I was detected using immunohistochemistry and in situ hybridization. Results Type I collagen was distributed in myocytes,and it encased each cardiac cell.The densities of collagen network in difference cardiac part were of disparity.Type I collagen was all expressed in fibrcyte and smooth muscle cells and endothelial cells in blood vessels of cardiac tissue.Conclusion The type I collagen is a main component of cardiac fibrous network,and its excreting cells are multifocal.