OBJECTIVETo investigate the ultrastructure of myocardium and gene expression of calcium handling proteins in diabetic rat heart.

METHODSDiabetes was induced in male Sprague-Dawley rats by a single injection of alloxanm (40 mg/kg ) and the rats in control group were injected with normal saline. At the end of 2, 4, 6 weeks after the induction of diabetes, the animals were sacrificed. The expression of calcium handling proteins was detected by reverse transcription-polymerase chain reaction (RT-PCR) and actin mRNA was used as internal standard. Heart tissue at the apex was obtained for light and electron microscope study.

RESULTSAt the end of 4 and 6 weeks, cardiosomatic ratio of diabetic rats was higher than that of control. Electron microscopy revealed a spectrum of subcellular remodeling in myocardium which was characterized by damaged myofibrils and mitochondria, dilated and swollen sarcoplasmic reticulum. Expression of phospholamban mRNAs was significantly increased, but 1,4,5-trisphosphate inositol receptor type 2, ryanodine receptor type 2 mRNAs were significantly decreased compared with those in the age-matched control rats. In contrast, the expression of sarco/endoplasmic reticulum Ca(2+)-ATPase mRNAs was not affected.

CONCLUSIONIn diabetic rat heart, gene expression of calcium handling proteins was characterized by up-regulation of phospholamban and down-regulation of sarcoplasmic reticulum calcium release channel while electron microscopic analysis of myocardium revealed a spectrum of subcellular remodeling.

Animals ; Calcium ; metabolism ; Calcium Channels ; metabolism ; Calcium-Binding Proteins ; biosynthesis ; genetics ; metabolism ; Diabetes Mellitus, Experimental ; metabolism ; pathology ; Endoplasmic Reticulum ; metabolism ; ultrastructure ; Male ; Myocardium ; metabolism ; ultrastructure ; RNA, Messenger ; biosynthesis ; genetics ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Sarcoplasmic Reticulum ; metabolism ; ultrastructure

OBJECTIVETo investigate the role of heme oxygenase-1 (HO-1) and its catalyst carbon monoxide (CO) in the development of myocardial damage and the effects of zinc protoporphyrin IX (ZnPPIX), an inhibitor of HO-1 on myocardium of mice with acute viral myocarditis.

METHODSA total of 112 inbred male Balb/C mice 4 - 6 weeks of age were divided randomly into 3 groups: the control group (C group, n = 32), the viral myocarditis group (V group, n = 40) and ZnPPIX group (Z group, n = 40). The Z and V groups were inoculated intraperitoneally (i.p.) with 0.1 ml of 10(-4.36) tissue culture infectious dose 50% (TCID(50))/ml Coxsackie virus B3 (CVB(3)) to produce viral myocarditis model on day 0, C group was injected i.p. with virus-free 1640 culture culture medium 0.1 ml at the same time, then operation was done as follows: the mice of group C and group V were injected i.p. with 0.1 ml NS each day. The mice of group Z were injected i.p. with 40 micromol per kilogram of body weight ZnPPIX (HO-1 inhibitor) qod. Eight mice of each group were sacrificed on days 4, 8, 15 and 21, respectively. The blood specimens were collected by taking out the eyeballs to test for the content of carboxyhemoglobin (COHb) using spectrophotometry and cardiac troponin I (cTnI) using chemiluminescent immunoassay. The hearts tissue slides were also stained by immunohistochemistry (IHC) for HO-1 and in situ hybridization (ISH) for HO-1 mRNA. The histological and ultrastructural changes were observed under light and electron microscopes.

RESULTS(1) The histopathological changes of myocardial cells: in the V and Z groups myocardial inflammatory cells infiltration reached the peak on day 8, the Z group histopathological scores were significantly lower than those in V group on day 8 (2.40 +/- 0.31 vs. 1.73 +/- 0.24, P < 0.01) and on day 15 (1.78 +/- 0.29 vs. 1.43 +/- 0.23, P < 0.05). No inflammation was present in group C. (2) The changes of serum cTnI level in both V and Z groups were significantly higher than those in C group on day 4, 8 and 15 (P < 0.01). The level in Z group was significantly lower than that in V group on day 4 [(6.074 +/- 1.475) ng/ml vs (7.911 +/- 1.225) ng/ml, P < 0.05] and day 8 [(0.821 +/- 0.294) ng/ml vs (1.480 +/- 0.454) ng/ml, P < 0.05]. (3) The changes of blood COHb level: compared with V group, in Z group the COHb level was lower on day 4 (P < 0.05) and day 15 (P < 0.01) after CVB(3) inoculation. Surprisingly, in Z group COHb level elevated suddenly on day 8 and showed conspicuously higher than that of V group (P < 0.01). (4) The result of HO-1 IHC staining: in both V and Z group myocardial cells had positive expression, while C group did not. (5) The results of HO-1 ISH were similar to those of HO-1 IHC, the A values of group Z was significantly lower than that of group V on day 4, 15 and 21(P < 0.01), but on day 8 it was higher than that of group C (P < 0.05).

CONCLUSIONHO-1 inhibitor, ZnPP not only could inhibit HO-1 overexpression but also could induce HO-1 expression temporarily and protect against myocardial injury at the early stage of acute viral myocarditis.

Animals ; Heme Oxygenase-1 ; antagonists & inhibitors ; Male ; Mice ; Mice, Inbred BALB C ; Myocarditis ; enzymology ; metabolism ; pathology ; virology ; Myocardium ; pathology ; ultrastructure ; Protoporphyrins ; pharmacology ; Virus Diseases ; metabolism ; pathology

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

OBJECTIVE: To investigate whether morphine preconditioning has the delayed protective effect on rabbit myocardium. METHODS: Thirty New Zealand white rabbits were randomly divided into a NS group, a Mor-12 group and a Mor-24 group (n=10). In the Mor-12 group and Mor-24 group, morphine (3 mg/kg) was infused into rabbits, while the same volume of normal saline (NS) was given to rabbits in the NS group. Twelve hours after morphine infusion in the Mor-12 group, 24 h after NS or morphine infusion in the NS group and Mor-24 group, rabbits were subjected to 30 min left anterior descending coronary artery occlusions and were reperfused for 120 min. In 8 of the 10 rabbits in each group, arterial blood samples were taken before the ischemia (T1), 30 min after the ischemia (T2) and 120 min after the reperfusion (T3) to determine the concentration of cardiac troponin I (cTnI), and the myocardial infarct area was determined at the end of reperfusion. In the other 2 of the 10 rabbits in each group,the cell ultramicro-structure injury of myocardium was examined by electron microscope at the end of reperfusion. RESULTS: The concentration of cTnI at T2 and T3 in the Mor-24 group was lower than that in the NS group and Mor-12 group.The myocardial infarct size, and cell ultramicrostructure injury of myocardium in the Mor-24 group were decreased compared with the NS group and Mor-12 group. CONCLUSION Morphine preconditioning has delayed protective effect on rabbit myocardium.
Animals ; Ischemic Preconditioning, Myocardial ; methods ; Morphine ; pharmacology ; Myocardial Reperfusion Injury ; pathology ; prevention & control ; Myocardium ; metabolism ; ultrastructure ; Rabbits ; Random Allocation ; Time Factors ; Troponin I ; blood

Confocal laser scanning microscopy(CLSM) is a new technique for microscopic imaging, which can collect the transverse section image of the samples and produce three-dimensional reconstruction and present higher spatial resolution than the conventional light microscope. As a precision instrument for the microscopic image, it plays an important role in forensic pathology. The article reviews the recent research achievements from sudden cardiac death, bullet wound and nervous system damage, etc, and explores the potential applications of the forensic pathology research and forensic practice.
Calcium/metabolism* ; Craniocerebral Trauma/pathology* ; Death, Sudden, Cardiac/pathology* ; Forensic Pathology/methods* ; Humans ; Image Processing, Computer-Assisted ; Microscopy, Confocal ; Myocardium/ultrastructure* ; Sensitivity and Specificity ; Trauma, Nervous System/pathology* ; Wounds and Injuries/pathology* ; Wounds, Gunshot/pathology*

OBJECTIVE: This study was performed to detect the phosphorylation state of Cx43 in human left ventricular myocardium among sudden deaths caused by acute myocardial ischemia (AMI) especially sudden coronary death (SCD) and control groups. And then evaluate the significance of these findings in diagnosing the early pathological changes of acute myocardial ischemia. METHODS: Immunohistochemistry (IHC) SP techniques were adopted to detect the phosphorylation state of Cx43 in the left ventricular myocardium samples of 45 deceased, which classified as group I--SCD, group II & III (other two groups of AMI) and Group IV & V (two control groups, sudden death caused by lethal acute cranio-cerebral injury or pathologic intracranial hemorrhage). In addition, we selected anti-Pan-Cadherin (construction protein of adherent junctions on the intercalated disc) and PHA-E+L/Bio, to detect the integration of myocardial mechanical coupling and membranes (applying affinityhistochemistry, AHC) respectively. RESULTS: (1) Phosphorylated Cx43 positive staining was almost invisible in Group I, II and III or scattered in sarcoplasm in few samples; but it was assembling at the IDs clearly in group IV and V. (2) Strongly positive staining of Pan-Cadherin could be observed at the IDs and (3) integrated myocardial membranes were found in all samples. CONCLUSION These findings suggested that compared with the control groups, the integration of myocardial mechanical coupling and membranes did not alter in AMI. But Cx43, the key protein of electrical coupling on myocardial gap junctions, occurred dephosphorylation remarkably in AMI. Thus applying IHC techniques to detect the Cx43 dephosphorylation in human left ventricular myocardium maybe useful to recognize the onset of arrhythmia in AMI, especially in SCD whose myocardium without apparent morphological changes.
Acute Disease ; Adolescent ; Adult ; Aged ; Arrhythmias, Cardiac/pathology* ; Connexin 43/metabolism* ; Death, Sudden, Cardiac/pathology* ; Female ; Gap Junctions/metabolism* ; Heart Ventricles/pathology* ; Humans ; Immunohistochemistry ; Male ; Middle Aged ; Myocardial Ischemia/pathology* ; Myocardium/ultrastructure*

OBJECTIVETo study the effects of different doses of taurine (Tau) on calcium ion concentration ([Ca2+]i) and ATPase on cardiocyte membrane of diastole heart failure rats.

METHODDiastole heart failure model was established by the coarctation of abdominal aorta. Four weeks after operation, forty diastole heart failure rats were divided into four groups randomly as follows, model (normal saline 2 mL), taurine (400 mg x kg(-1) x d(-1)), taurine (200 mg x kg(-1) x d(-1)), taurine (100 mgx kg(-1) x d(-1)), with 10 rats for each group (n=10), and 10 sham operation rats was taken as control(normal saline, 2 mL). After 4 weeks administration, Isolate single cardiocyte by enzymatic isolation method which were loaded with Ca2+-sensitive fluorescent indicator Fluo-3/AM. [Ca2+]i was measured by laser scanning confocal microscope [LSCM], and represented it by fluorescent intensity [FI]; ATPase activity of cell membrane was measured by the method of enzymatic reaction chromatometry.

RESULTCompared with the control group, [Ca2+]i in cardiocyte increased markedly and the ATPase activity of cardiocyte membrane decreased significantly in the model group. Compared with the model group, fluorescent value decreased and ATPase activity increased significantly in Tau high-dose group; fluorescence value and ATPase activity decreased significantly in Tau mid-dose group; fluorescent value decreased and ATPase activity increased significantly in Tau low-dose group.

CONCLUSIONLarge dosage of Tau can increase ATPase activity on cardiocyte membrane, improve [Ca2+]i in cardiocyte and antagonise calcium overload of DHF rats.

Adenosine Triphosphatases ; metabolism ; Animals ; Calcium ; metabolism ; Diastole ; drug effects ; Disease Models, Animal ; Female ; Heart Failure ; drug therapy ; metabolism ; Male ; Myocardium ; pathology ; ultrastructure ; Myocytes, Cardiac ; drug effects ; metabolism ; pathology ; Rats ; Rats, Wistar ; Taurine ; administration & dosage ; pharmacology ; therapeutic use

OBJECTIVETo investigate the protective effects of preconditioning morphine on rabbit myocardium during ischemia-reperfusion.

METHODSThirty New Zealand male white rabbits were randomly assigned to three groups: control, I/R and morphine groups. In morphine group 1.0 mg/kg morphine was given preoperationaly, in control and I/R groups 1.0 ml/kg NS was given. Twenty-four hours later rabbits in morphine and I/R groups underwent 40 min of coronary occlusion followed by 2 hours of reperfusion; for control group only sham operation was performed. At the end of the reperfusion, infarct size (IS) and area at risk (AAR) were defined by Evans blue and TTC staining. At the end of the reperfusion blood samples were taken for determination of plasma SOD activity and MDA levels. The heart was harvested and levels of the HSP27 were determined by Western blot, and the heart ultrastructures were observed under the electron microscopy.

RESULTSCompared with I/R group,morphine significantly reduced infarct size (21.5%+/-2.4% Compared with 37.8%+/-1.7%, P<0.05). The morphine had a lower level of MDA and higher levels of SOD and HSP27 than those in I/R.

CONCLUSIONPreconditioning of morphine demonstrates cardioprotective effect on ischemia/reperfusion injury, which may be associated with increased HSP27 levels in the heart.

Animals ; HSP27 Heat-Shock Proteins ; metabolism ; Ischemic Preconditioning, Myocardial ; methods ; Male ; Malondialdehyde ; metabolism ; Morphine ; pharmacology ; Myocardial Reperfusion Injury ; pathology ; prevention & control ; Myocardium ; metabolism ; ultrastructure ; Rabbits ; Random Allocation ; Superoxide Dismutase ; metabolism

OBJECTIVETo observe the effect of heart protection on diabetic cardiomyopathy in rats by tripterysium glucosides.

METHODThe rat diabetic cardiomyopathy rats model are made by streptozotocin, then divided into tripterysium glucosides group (n=8) and model group (n=8). In addition, the control group is established (n=8). Glucosides group was orally administrated tripterysium glucosides (18 mg x kg(-1)), the control groups was orally administrated same volume NS for 3 months. Blood sugar, heart function and cardiac index were detected after 3 months. Immunohistochemical techniques were used to detect NF-kappaB and ICAM-1 expression. Ultrastructure of cardiac muscle cell were observed by electronmicroscope.

RESULTCompared with model group, cardiac index was decreased after tripterysium glucosides administration, and LVSP, LVEDP, + dp/dtmax, -dp/dtmax, were improved, and the expression of nuclear Factor-kappaB (NF-kappaB) and intercellular adhension molecule-1 (ICAM-1) was inhibited. Ultrastructure of cardiac muscle cell such as mitochondrion and cardiac muscle fibers was atttenuated.

CONCLUSIONTripterysium glucosides could protect rat diabetic cardiomyopathy rats heart. These function may be related to inflammatory reaction inhibition and immunosuppression of tripterysium glucosides.

Animals ; Blood Glucose ; metabolism ; Cardiomyopathies ; etiology ; metabolism ; pathology ; physiopathology ; Diabetes Mellitus, Experimental ; complications ; Gene Expression Regulation ; drug effects ; Glucosides ; administration & dosage ; pharmacology ; therapeutic use ; Heart ; drug effects ; Intercellular Adhesion Molecule-1 ; metabolism ; Male ; Myocardium ; ultrastructure ; NF-kappa B ; metabolism ; Rats

OBJECTIVETo explore the synergistic protection of Danhong Injection (丹红注射液, DHI) and ischemic postconditioning on myocardial reperfusion injury in minipigs.

METHODSAcute myocardial infarction model was made by balloon occlusion in left anterior descending coronary artery (LAD) of minipigs, and then postconditioning was simulated through inflation/deflation of the angioplasty balloon. Minipigs were divided into four groups: the sham operation group (SH group), the ischemia/reperfusion group (I/R group), the ischemic postconditioning group (POC group) and DHI combined with ischemic postconditioning group (PAD group, DHI 20 mL through ear vein), six in each group. After 24-h continuous observation, myocardial infarction size was assessed by triphenyltetrazolium staining (TTC). Morphological changes of ischemic myocardium were observed by light microscopy, and cardiomyocyte ultrastructure was studied with electron microscopy. The superoxide dismutase (SOD) and malondialdehyde (MDA) activity in heart homogenates were measured by a biochemical method.

RESULTSThe myocardial infarction size was smaller in the POC group than in the I/R group (0.26 ± 0.02 vs. 0.37 ± 0.09, P<0.05), and the PAD group (0.14 ± 0.08) displayed a significantly reduced infarction size relative to the I/R group (P<0.01) and POC group (P<0.05). The damage of myocardial tissue was severe in the I/R group shown by light and electron microscopy: myocardial fibers disorder, sarcoplasmic dissolution, myofilament fracture, mitochondria swelling and even vacuolization formation and a large number of inflammatory cell infiltrations. Compared with the I/R group, reduction of reperfusion injury in the PAD group included more orderly arranged myocardial fibers, less infiltration of inflammatory cells and maintenance of mitochondrial integrity. Compared with the I/R group, the damage of myocardial tissue in the POC group was improved, but not as significant as that in the PAD group. SOD levels in the POC group and the PAD group were significantly higher than those in the I/R group (96.96 ± 13.43, 112.25 ± 22.75 vs. 76.32 ± 10.63, P<0.05), and MDA was significantly lower in the POC group and the PAD group compared to the I/R group (1.27 ± 0.19, 1.09 ± 0.21 vs. 1.47 ± 0.16, P<0.05).

CONCLUSIONDHI and ischemic postconditioning show a synergistic cardioprotection on myocardial reperfusion injury in minipigs.

Animals ; Coronary Angiography ; Drugs, Chinese Herbal ; administration & dosage ; therapeutic use ; Injections ; Ischemic Postconditioning ; Malondialdehyde ; metabolism ; Myocardial Infarction ; complications ; pathology ; Myocardial Reperfusion Injury ; complications ; drug therapy ; prevention & control ; Myocardium ; enzymology ; pathology ; ultrastructure ; Superoxide Dismutase ; metabolism ; Swine ; Swine, Miniature