Objective To observe the skin ultrastructure change of electric shock death rats and to test the expression changes of hypoxia-inducible factor-2α （HIF-2α） and heart type-fatty acid-binding protein （H-FABP） of myocardial cells, in order to provide basis for forensic identification of electric shock death. Methods The electric shock model of rats was established. The 72 rats were randomly divided into control group, electric shock death group and postmortem electric shock group. Each group was divided into three subgroups, immediate （0 min）, 30 min and 60 min after death. The skin changes of rats were observed by HE staining, the changes of skin ultrastructure were observed by scanning electron microscopy, and the expression of HIF-2α and H-FABP in rats myocardium was tested by immunohistochemical staining. Results The skin in the electric shock death group and postmortem electric shock group had no significant difference through the naked eye or by HE staining. Under the scanning electron microscope, a large number of cellular debris, cells with unclear boundaries, withered cracks, circular or elliptical holes scattered on the cell surface and irregular edges were observed. A large number of spherical foreign body particles were observed. Compared with the control group, the expression of HIF-2α in all electric shock death subgroups increased, reaching the peak immediately after death. In the postmortem electric shock group, HIF-2α expression only increased immediately after death, but was lower than that of electric shock death group （P<0.05）. Compared with the control group, the expression of H-FABP in all subgroups of electric shock death group and postmortem electric shock group significantly decreased. The expression of H-FABP in all subgroups of electric shock death group was lower than that of the postmortem electric shock group （P<0.05）. Conclusion Electric shock can increase HIF-2α expression and decrease H-FABP expression in the myocardium, which may be of forensic significance for the determination of electric shock death and identification of antemortem and postmortem electric shock.
Animals ; Autopsy ; Basic Helix-Loop-Helix Transcription Factors/metabolism* ; Fatty Acid Binding Protein 3/metabolism* ; Myocardium/metabolism* ; Myocytes, Cardiac/metabolism* ; Rats ; Skin/ultrastructure*

BACKGROUNDCoronary microembolization (CME) has been frequently seen in acute coronary syndromes and percutaneous coronary intervention. Small animal models are required for further studies of CME related to severe prognosis. This study aimed to explore a new mouse model of CME.

METHODSThe mouse model of CME was established by injecting polystyrene microspheres into the left ventricular chamber during 15-s occlusion of the ascending aorta. Based on the average diameter and dosage used, 30 C57BL/6 male mice were randomly divided into five groups (n = 6 in each): 9 μm/500,000, 9 μm/800,000, 17 μm/200,000, 17 μm/500,000, and sham groups. The postoperative survival and performance of the mice were recorded. The mice were sacrificed 3 or 10 days after the surgery. The heart tissues were harvested for hematoxylin and eosin staining and Masson trichrome staining to compare the extent of inflammatory cellular infiltration and fibrin deposition among groups and for scanning transmission electron microscopic examinations to see the ultrastructural changes after CME.

RESULTSSurvival analysis demonstrated that the cumulative survival rate of the 17 μm/500,000 group was significantly lower than that of the sham group (0/6 vs. 6/6, P = 0.001). The cumulative survival rate of the 17 μm/200,000 group was lower than those of the sham and 9 μm groups with no statistical difference (cumulative survival rate of the 17 μm/200,000, 9 μm/800,000, 9 μm/500,000, and sham groups was 4/6, 5/6, 6/6, and 6/6, respectively). The pathological alterations were similar between the 9 μm/500,000 and 9 μm/800,000 groups. The extent of inflammatory cellular infiltration and fibrin deposition was more severe in the 17 μm/200,000 group than in the 9 μm/500,000 and 9 μm/800,000 groups 3 and 10 days after the surgery. Scanning transmission electron microscopic examinations revealed platelet aggregation and adhesion, microthrombi formation, and changes in cardiomyocytes.

CONCLUSIONThe injection of 500,000 polystyrene microspheres at an average diameter of 9 μm is proved to be appropriate for the mouse model of CME based on the general conditions, postoperative survival rates, and pathological changes.

Animals ; Brain ; pathology ; Coronary Occlusion ; pathology ; surgery ; Coronary Vessels ; pathology ; surgery ; ultrastructure ; Disease Models, Animal ; Embolization, Therapeutic ; Kidney ; pathology ; Male ; Mice ; Mice, Inbred C57BL ; Microscopy, Electron, Scanning Transmission ; Myocardium ; pathology ; Platelet Aggregation ; physiology

OBJECTIVETo investigate the effects of hydrogen sulfide (H₂S) on oxidative stress and endoplasmic reticulum stress (ERS) in a rat model of diabetic cardiomyopathy (DCM).

METHODSThirty male SD rats were randomly divided into control group, diabetes group and treatment group( n = 10). Intraperitoneal injection of streptozotocin was utilized to establish a rat model of DCM. The rats with DCM in treatment group were intraperitoneally injected with NaHS solution. After treated for 12 weeks, the hearts isolated from rats were perfused on a langendorff apparatus. The ventricular hemodynamic parameters were measured. The ultrastructures of myocardium were observed using electron microscopy. The content of malondialdehyde (MDA), the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in myocardial tissue were determined by spectrophotometry. The expressions of C/EBP homologous protein( CHOP), glucose-regulated protein 78 (GRP78) and Caspase 12 at mRNA level in myocardium were detected using RT-PCR.

RESULTSCompared with control group, the cardiac function and myocardial ultrastructure were damaged obviously in diabetic rats. In myocardial tissue, the content of MDA was increased, while the activities of SOD and GSH-Px were decreased. CHOP, GRP78 and Caspase 12 mRNA expressions were increased significantly. Compared with diabetes group, cardiac function and myocardial ultrastructure damage were improved in treatment group. The content of MDA was decreased, while the activities of SOD and GSH-Px were increased significantly. The mRNA levels of CHOP, GRP78 and Caspase 12 were increased.

CONCLUSIONH2S can protect myocardium in diabetic rats, maybe it is related to reduce oxidative stress damage and inhibition of the ERS-induced apoptosis pathway.

Animals ; Apoptosis ; Caspase 12 ; metabolism ; Diabetes Mellitus, Experimental ; drug therapy ; Diabetic Cardiomyopathies ; drug therapy ; Endoplasmic Reticulum Stress ; Glutathione Peroxidase ; metabolism ; Heat-Shock Proteins ; metabolism ; Hydrogen Sulfide ; pharmacology ; Male ; Malondialdehyde ; metabolism ; Myocardium ; ultrastructure ; Oxidative Stress ; Rats ; Streptozocin ; Superoxide Dismutase ; metabolism ; Transcription Factor CHOP ; metabolism

OBJECTIVE: To investigate the effect of hydrogen sulfide (H2S) on cardiac myosin light chain kinase (MLCK) expression in diabetic rats.
 METHODS: A total of 32 male SD rats were randomly divided into a normal control group (NC group), a diabetic control group (DM), a NaHS treatment group (DM+NaHS) and a NaHS group (NaHS) (n=8 in each group). Intraperitoneal injection of streptozotocin was utilized to establish Type 1 diabetic rat model. The diabetic rats in the DM+NaHS and NaHS groups were intraperitoneally injected with 28 μmol/kg NaHS solution. Eight weeks later, the ventricular hemodynamic parameters, the ratio of heart weight/body weight (HW/BW ratio), the levels of lactate dehydrogenase (LDH) and creatine kinase MB isozyme (CK-MB) in serum were determined. The ultrastructures of myocardium were observed under electron microscopy. The expressions of MLCK mRNA and protein level in myocardium were detected by RT-PCR and Western blot, respectively.
 RESULTS: Compared with the NC group, there was no significant difference in the various indexes in the NaHS group (all P>0.05). The function of left ventricular contract and relaxation were decreased obviously in diabetic rats, while the HW/BW ratio was increased (all P<0.01). The levels of LDH and CK-MB were increased (both P<0.01) in serum, while the levels of MLCK mRNA and protein were decreased significantly (both P<0.01) in myocardial tissues. Compared with the DM group, the left ventricular hemodynamic parameters and myocardial ultrastructure damage were improved in the DM+NaHS group, while the HW/BW ratio was decreased (all P<0.05). The levels of LDH and CK-MB were decreased (both P<0.01), while the levels of MLCK mRNA and protein were increased significantly (both P<0.01).
 CONCLUSION H2S can protect myocardium in diabetic rats, which may be associated with upregulation of cardiac MLCK.
Animals ; Cardiotonic Agents ; pharmacology ; Creatine Kinase, MB Form ; blood ; Diabetes Mellitus, Experimental ; drug therapy ; Heart ; drug effects ; Hemodynamics ; Hydrogen Sulfide ; pharmacology ; L-Lactate Dehydrogenase ; blood ; Male ; Myocardium ; ultrastructure ; Myosin-Light-Chain Kinase ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Sulfides ; pharmacology ; Ventricular Function, Left ; drug effects

OBJECTIVETo innovatively establish a new platform of myocardial ischemia-reperfusion injury (MIRI) animal model by observing abnormal savda carrier MIRI indicators, and to observe changes of myocardial ultrastructure.

METHODSAccording to Uyghur medical theories, an abnormal savda carrier animal model was established and confirmed using multifactor, and then MIRI models set up. Totally 36 male white SD rats were randomly divided into the normal sham-operation group, the normal operation group, the model sham-operation group, and the model operation group, 9 in each group. ECG changes, myocardial enzymes (CK-MB), and cardiac troponin (cTnT), and ultramicrostructures were observed.

RESULTSCompared with the normal sham-operation group, some damage of ultramicrostructures occurred in heart muscles of rats in the normal operation group and the model operation group, such as lowered myoplasm density, loosely arranged myofilament, dilated myofibris, reduced mitochondria number, vacuole and swelling mitochondrion. Ultramicrostructural damage of cardiac muscle cells was more severe in rats of the model operation group. Compared with the normal sham-operation group, CK-MB and cTnT increased in the normal operation group with statistical difference (P < 0.01). Compared with the normal sham-operation group, there was no statistical difference in CK-MB or cTnT in the model sham-operation group (P > 0.05). Compared with the model operation group, CK-MB and cTnT obviously decreased in the model sham-operation group and the normal operation group with statistical difference (all P < 0.01).

CONCLUSIONAbnormal savda carrier MIRI model established in this experiment could provide favorable conditions for further MIRI intervention treatment.

Animals ; Disease Models, Animal ; Male ; Medicine, Traditional ; Myocardial Reperfusion Injury ; Myocardium ; ultrastructure ; Myocytes, Cardiac ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo identify clinical and pathological features of giant cell myocarditis.

METHODSClinical presentation and follow-up data of three patients with giant cell myocarditis were collected.Gross, histopathological, immunohistological and ultrastructural findings of extransplantated hearts of the patients were documented.

RESULTSGrossly, multifocal involvement of the myocardium with variably dilated cardiac chambers were observed in all 3 cases.Histological examination revealed pronounced focal inflammatory infiltrates with multinucleated giant cells. Multinucleated giant cells were positive for CD68 and CD11b immunostains but were negative for CD163 in all cases. Transmission electron microscopy showed that the multinucleated giant cells derived from fusion of several macrophages with adherent lymphocytes and secretary cells. Clinically, the overall patient condition improved in all three cases after heart transplantation.One patient experienced acute cellular rejection (2R level) 4 months after transplantation, but recovered after treatment. One patient developed multinucleated giant cells observed in heart biopsy two weeks after transplantation.

CONCLUSIONSGiant-cell myocarditis is a rare disease of adult, and cardiac transplantation could improve the clinical outcome. Multinucleated giant cell in the myocarditis lesions were derived from macrophages, likely participating in the immune response. Endomyocardial biopsy is important for the diagnosis of giant cell myocarditis.

Acute Disease ; Adult ; Biopsy ; Giant Cells ; pathology ; ultrastructure ; Heart Transplantation ; Humans ; Lymphocytes ; pathology ; Macrophages ; pathology ; Microscopy, Electron, Transmission ; Myocarditis ; pathology ; Myocardium ; pathology ; ultrastructure

OBJECTIVETo investigate the effects of recombinant human growth hormone (rhGH) on the morphology and function of the left cardiac ventricle in young rats with dilated cardiomyopathy (DCM), and to evaluate the efficacy and safety of rhGH in the treatment of DCM.

METHODSSixty male Sprague-Dawley rats were randomly and equally assigned to control group, DCM group, and rhGH group. Furazolidone (0.25 mg/g) was given by gavage for 12 weeks to prepare the DCM model. Rats in the rhGH group received an intraperitoneal injection of rhGH (0.15 U/kg) once per day for 12 weeks, while rats in the DCM group received an equal volume of normal saline instead. Rats in the control group did not receive any treatment. Cardiac indices, serum biochemical parameters, hemodynamic indices, cardiac histopathological changes, and levels of myocardial collagen fibrils in each group were determined using Doppler echocardiography, enzyme-linked immunosorbent assay, multi-channel physiological recorder, light and electron microscopy, and picrosirius red staining plus polarization microscopy, respectively.

RESULTSCompared with the control group, rats in the DCM group had significantly increased cardiac chamber size, significantly reduced ventricular wall thickness, and significantly decreased fractional shortening (FS) and ejection fraction (EF) (P<0.05). Rats in the rhGH group had significantly improved cardiac chamber size, ventricular wall thickness, FS, and EF compared with the DCM group (P<0.05). Those indices in the rhGH group were similar to those in the control group (P>0.05). There were significant differences in serum biochemical parameters and hemodynamic indices between the DCM and control groups (P<0.05). Compared with the DCM group, the rhGH group had significantly improved serum biochemical parameters and hemodynamic indices (P<0.05). Those indices in the rhGH group were similar to those in the control group (P>0.05), except for the levels of insulin-like growth factor-1 and insulin-like growth factor-binding protein-3. The DCM group had a significantly higher collagen type I/collagen type III (Col I/Col III) ratio in the myocardium than the control group (P<0.05), and there was no significant difference in the Col I/Col III ratio between the control and rhGH groups (P>0.05).

CONCLUSIONSrhGH plays a certain role in improvement in the morphology and function of the left cardiac ventricle in young rats with DCM.

Animals ; Cardiomyopathy, Dilated ; drug therapy ; pathology ; Collagen Type III ; analysis ; Echocardiography ; Hemodynamics ; drug effects ; Human Growth Hormone ; therapeutic use ; Male ; Myocardium ; pathology ; ultrastructure ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo observe the effects of manganese sulfate on blood pressure, myocardial ultrastructure and heart organ index of rats.

METHODSForty male SPF SD rats were randomly divided into 4 groups: control group (0 mg/kg), 5 mg/kg dose group, 15 mg/kg dose group and 25 mg/kg dose group, 10 rats each group. Intraperitoneal injection was performed for six months, by five times each week, the rat blood pressure was measured by tail cuff method, and the heart organ index of the rats was computed. Three rats were selected from each group randomly, and the myocardial ultrastructure of the rats was observed by using transmission electron microscopy (TEM). The BMD and BMDL between manganese sulfate injected dose and the rats heart organ index were evaluated by BMD (Benchmark Dose).

RESULTSThere was no significant of blood pressure between the experimental group and the control group (P > 0.05).The heart organ indexes of the four groups were 0.24% ± 0.10%, 0.25% ± 0.02%, 0.26% ± 0.02%, and 0.24% ± 0.02%. Statistical significance of heart organ indexes was found between the 15 mg/kg dose group and the control group (P < 0.05). Observed by TEM, we found that-different degrees of mitochondrial crest fracture or disappear, mitochondria swelling, hydropic change and myocardial fibers degeneration happened in the rats of the three exposed groups, but not the control group. The BMD and BMDL were calculated as 9.33 mg/kg and 4.28 mg/kg in the study of manganese sulfate injected dose and the rats heart organ index.

CONCLUSIONChronic manganese poisoning can lead to myocardial mitochondria superfine lesions, myocardial fiber damage and heart organ index change in rats.

Animals ; Male ; Manganese Compounds ; Mitochondria ; drug effects ; ultrastructure ; Myocardium ; ultrastructure ; Myocytes, Cardiac ; drug effects ; ultrastructure ; Rats ; Rats, Sprague-Dawley ; Sulfates ; toxicity ; Toxicity Tests

OBJECTIVETo investigate the protective effect of high-pressure carbon monoxide for preservation of ex vivo rabbit heart graft in comparison with the conventional HTK cardioplegic solution preservation.

METHODSHeart grafts isolated from 85 New Zealand rabbits were randomly divided into Naive group (n=5), HTK group (n=40) and CO group (n=40). The grafts underwent no preservation procedures in Naive group, preserved at 4 degrees celsius; in HTK cardioplegic solution in HTK group, and preserved at 4 degrees celsius; in a high-pressure tank (PO2: PCO=3200 hPa: 800 hPa) in CO group with Krebs-Henseleit solution perfusion but without cardioplegic solution. After preservation for 2, 4, 6, 8, 10, 14, 18, and 24 h, 5 grafts from the two preservation groups were perfused for 30 min with a modified Langendorff apparatus and examined for left ventricular systolic pressure (LVSP), left ventricular diastolic pressure (LVDP), arrhythmia score (AS), myocardial ultrestructure, and cardiac enzyme profiles.

RESULTSAfter preservation for 6 to 24 h, the cardiac enzyme profiles and systolic and diastolic functions were significantly better in CO group than in HTK group, but these differences were not obvious between the two groups after graft preservation for 2 to 4 h. Significant changes in the myocardial ultrastructures occurred in the isolated hearts after a 24-h preservation in both CO and HTK groups, but the myocardial damages were milder in CO group.

CONCLUSIONPreservation using high-pressure carbon monoxide can better protect isolated rabbit heart graft than the conventional HTK preservation approach especially for prolonged graft preservation.

Animals ; Carbon Monoxide ; Cardioplegic Solutions ; Glucose ; Heart ; physiology ; Heart Transplantation ; Myocardium ; ultrastructure ; Rabbits ; Tissue Preservation ; methods ; Tromethamine

OBJECTIVETo investigate the inhibitory effect of tetramethylpyrazine (Tet) preconditioning on overload training-induced myocardial apoptosis in rats, and to explore cardioprotective mechanisms of Tet preconditioning.

METHODSA total of 25 male Sprague-Dawley rats were randomly divided into three groups, including the control group (n=5), the overload training group (overload training for 8 weeks, n=10), and the Tet preconditioning group (Tet preconditioning for 8 weeks before overload training, n=10). After 8 weeks, cardiac structure and myocardial apoptosis were analyzed by histology, transmission electron microscopy, and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay staining. The expressions of Bcl-2, Bax, Caspase-3, and Caspase-9 in myocardium were evaluated by immunohistochemical staining.

RESULTSOverload training caused swelling, disorder, partial rupture, and necrosis of myocardial focal necrotic fibers, as well as mitochondrial vacuolization, cristae rupturing, and blurring. In contrast, Tet preconditioning attenuated the swelling of myocardial fibers, decreased the amount of ruptured fibers, and inhibited mitochondrial vacuolization, resulting in clear cristae. Overload training significantly increased Bax expression and decreased Bcl-2/Bax ratio when compared with the control group (P<0.01). Conversely, Tet preconditioning significantly increased Bcl-2 expression and the Bcl-2/Bax ratio as compared with the overload training group (P<0.05). Overload training dramatically increased the expressions of Caspase-3 and Caspase-9 when compared with the control groupP<0.05). Following Tet preconditioning, the expression of Caspase-3 was significantly reduced compared with the overload training group (P<0.05), while Caspase-9 expression showed a slight decline (P>0.05).

CONCLUSIONTet preconditioning increased the expression of Bcl-2 and reduced the expression of Caspase-3, thereby attenuating overload training-induced myocardial apoptosis, protecting against overload training-induced myocardial injury, and reducing damage to the myocardium due to overload training.

Animals ; Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Caspase 9 ; metabolism ; Immunohistochemistry ; Male ; Myocardium ; enzymology ; pathology ; ultrastructure ; Pyrazines ; pharmacology ; Rats, Sprague-Dawley ; bcl-2-Associated X Protein ; metabolism